Seattle Mariners general manager Jack Zduriencik is expected to make significant changes to the club’s roster over the next month. / Sportspress Northwest file

After a turgid start to 2014 (10-14 in April) that threatened to sink the season, the Mariners (49-42) are nearing the All-Star break seven games above .500 and still in contention for a wild-card spot — even though they have lost four of their past six, scoring  seven runs over that span after tallying 28 in the previous three.

The sudden plunge into offensive lameness — apparently part of this team’s DNA — against the two worst teams in the AL Central (Cleveland, Minnesota) means that overtaking Oakland for the AL West title is out of the question. But the Mariners have done enough through 91 games to make general manager Jack Zduriencik a buyer as the July 31 trade deadline nears.

Zduriencik needs to answer quickly Oakland’s two latest lines in the dirt, the acquisitions of Jeff Samardzija and Jason Hammel, with moves of his own. Even though rookie Roenis Elias and Chris Young have performed better than expected at the back of the rotation, Elias has hit a wall. Rocked early and often Wednesday night in an 8-1 defeat, he’s dropped his last three while posting a Horacio Ramirez-like ERA of 10.05.

If that doesn’t make urgent Zduriencik’s need for another starting pitcher, Oakland’s trade with the Chicago Cubs for Samardzija and Hammel does. And if that doesn’t, consider that Seattle is one of only four American League teams, and the only one in wild card contention, that has a sub.-500 record (26-28) against losing teams.

Obtaining a right-handed bat, a need for the Mariners since 2007, is particularly urgent. Seattle’s right-handed batters are hitting. 220, the worst mark in the American League and only marginally better than last year’s .208, the nadir number of the last decade. That has helped fuel a Safeco Field OPS of .649, worst in the AL West. How that .649 compares to the rest of the division:

But this goes beyond the AL West. In the AL, Kansas City is the only team apart from the Mariners with an OPS in its home park (Kauffman Stadium) under .700. In the National League, four teams have an OPS of less than .700 at home, but only San Diego’s .611 at Petco Park is worse than Seattle’s .649 at Safeco Field, where the Mariners have already been blanked seven times and narrowly avoided an eighth Wednesday night.

Imagine Seattle’s Safeco OPS if the front office hadn’t brought in the fences two years ago and signed Robinson Cano last offseason. Worst home-park OPS in the majors (and keep in mind that only once in Zduriencik’s tenure — 2009, .712 — have the Mariners been above .700 at home):

Through report and rumor, the Mariners have been linked to several potential acquisitions, among them Matt Kemp of the Dodgers, Marlon Byrd of the Phillies and Dayan Viciedo of the Chicago White Sox.

A two-time All-Star, Kemp is hitting .271 with eight home runs, 34 RBIs and an OPS of .768. He could fill a corner outfield role that Dustin Ackley (.229 BA, .627 OPS) can’t (time to concede that Zduriencik whiffed with Ackley). Kemp will cost, in the pocketbook and farm system, but if the Mariners don’t go for it now, when will they? The Mariners rarely have the opportunity that currently presents itself.

Although Byrd is 36, he’s an ideal mid-season rental candidate: 18 home runs, 52 RBIs, .797 OPS. Byrd isn’t a long-term fix, but Zduriencik doesn’t need that right now. He needs a fix for 71 games.

The Mariners had interest in Viciedo, a 25-year-old outfielder, during spring training. Viciedo delivered a 4-for-4 performance against the Mariners last week at U.S. Cellular Field, and ESPN.com’s Gordon Edes reported this week that Seattle is considering a two-player package that includes pitcher Brandon Maurer to get him.

The Mariners have made several deadline deals during Zduriencik’s time with the club (since 2008), all fire sales designed to unload rather than upgrade. Now it’s time for an upgrade before the Mariners endure another lame stretch of seven runs in six games.

Jack Zduriencik’s trade history

Since his hiring by the Mariners Oct. 22, 2008, Zduriencik has made more than 40 trades, starting with a Dec 10, 2008, three-team, 11-player swap fest that cost the club All-Star closer J.J. Putz but netted Gold Glove outfielder Franklin Gutierrez. Had Gutierrez not made seven trips to the disabled list between 2011-13 before deciding to sit out 2014 altogether, Zduriencik might have a great trade to boast about.

Instead, he’s still seeking an outfielder who can hit, in fact an outfield that can hit. Seattle fly-shaggers collectively average .247 this season with 15 home runs. Not much juice there.

The July 9, 2010 trade of Cliff Lee to Texas for Justin Smoak (that’s the way it’s settled out) was supposed to solve that issue, but Smoak developed into an over-sized version of Mario Mendoza.

Michael Pineda for Jesus Montero Jan. 23, 2012 carried the hope a formidable right-handed bat for a decade. But Montero became a five-tool guy in the worst sense – couldn’t run, hit, or field, couldn’t lay off the pharmaceuticals, couldn’t avoid third helpings in the buffet line.

The Mariners feature on their active roster only three players acquired in Zduriencik’s 40-plus trades: relievers Charlie Furbush and Danny Farquhar and first baseman Logan Morrison. A fourth, Endy Chavez, came to Seattle in the Putz-Gutierrez exchange, but has been released and re-signed by Seattle four times since.

For 40-plus trades, Zduriencik acquired two All-Stars (Cliff Lee, Brandon League), one Gold Glover (Gutierrez), and a 30-home run hitter (Russell Branyan). He traded or released all but Gutierrez. None of his trades resulted in a .300 hitter or 20-game winner. A 15-game winner would have been nice, but Zduriencik hasn’t gotten that, either.

Zduriencik has been adept at addressing short-term solutions to long-standing problems. LHP Jason Vargas won 36 games in four years (2009-12). David Aardsma (2009-10) and Brandon League (2010-11) combined to successfully close out 121 games. Branyan (2009-10) banged 46 home runs. Kendrys Morales hit 23 home runs in 2013. Furbush and Farquhar are part of one of the AL’s best bullpens. Logan Morrison is an upgrade over Smoak.

Zduriencik hasn’t parted with much. The only future All-Star he traded was impending free agent Cliff Lee, whom he wouldn’t have been able to sign after 2010 anyway. Doug Fister is 39-22 for Detroit and Washington since departing, Brandon Morrow 34-30 for Toronto, and Jason Vargas 17-11 for the Angels and Royals.

Zduriencik’s major deals:

Dec. 10, 2008: RHP J.J. Putz, RHP Sean Green and OF Jeremy Reed to the Mets and INF Luis Valbuena to Cleveland; acquired 1B Mike Carp, OF Endy Chavez, RHP Aaron Heilman, LHP Jason Vargas, OF Ezquiel Carrera, RHP Maikel and OF Franklin Gutierrez.The Mariners got 36 wins out of Vargas, a Gold Glove year (2010) out of Gutierrez and continue to receive production from Chavez after re-acquiring him in 2013. Had Guiterrez stayed healthy, this might have been one of Zduriencik’s best deals.

Jan. 20, 2009: LHP Fabian Williamson to Boston for RHP David Aardsma. Aardsma saved 69 games over two Seattle seasons (2009-10), but arm problems ended his career. Williamson never reached the majors.

July 10, 2009: SS Yuniesky Betancourt and cash to Kansas City for RHP Danny Cortez and LHP Derrick Saito. Betancourt hit .243 in five seasons after leaving Seattle. Cortez  (0-3, 5.91 in 14 games) and Saito (minors only) never amounted to anything.

July 11, 2009. RHP Justin Souza to Oakland A’s for SS Jack Hannahan: Souza never reached majors. Hannahan fit right in with the Mariners, hitting .230 in 167 games before Seattle sold him to the Red Sox in 2010.

July 29, 2009: SS Ronny Cedeno, C Jeff Clement and RHPs Aaron Pribanic, Brett Lorin and Nathan Adcock to Pittsburgh for SS Jack Wilson and RHP Ian Snell. The Mariners gave up nothing, including 2005 No. 1 pick Clement, and got nothing.

July 31, 2009: LHP Jarrod Washburn to Detroit for LHP Luke French and LHP Mauricio Robles. Washburn went 31-49 in four years with the Mariners but pitched in only eight games after leaving Seattle. French, 8-10, 5.37 in 24 games for Seattle, and Robles washed out.

Dec. 16, 2009: RHP Phillippe Aumont, RHP J.C. Ramierz and OF Tyson Gillies to Philadelphia for LHP Cliff Lee. Mariners received a great half out of Lee in 2010 (8-3, 2.24) and lost nothing in trading three minor leaguers for him. Aumont, Seattle’s No. 1 draft pick in 2007, has been used exclusively in relief during his three major league seasons.

Dec. 19, 2009: RHP Carlos Silva and $9 million to the Cubs for DH/OF Milton Bradley. Classic exchange of headaches. Bradley never played after leaving the Mariners in 2011. Silva had one year with the Cubs (10-6) and was done.

Dec. 23, 2009: RHP Brandon Morrow to Toronto for RHP Brandon League and minor league OF Johermyn Chavez. Morrow is 42-42 in five years with the Blue Jays, including 4-1, 2.85 in five starts against the Mariners. League saved 52 games for Seattle between (2010-12) and has 20 saves in three seasons since as a Dodgers’ setup man.

June 26, 2010: OF Ezequiel Carrera and SS Juan Diaz to Cleveland for 1B Russell Branyan. Branyan didn’t stay long with the Mariners, 173 games over the 2009-10 seasons. But he had 46 home runs during his stay, including a career-high 31 in 2009. Carrera never amounted to much in three MLB seasons, and Diaz was a career minor leaguer.

July 9, 2010: LHP Cliff Lee to Texas for 1B Justin Smoak, RHP Blake Beavan, RHP Josh Lueke, INF Matt Lawson and cash. Best part of this deal is that Seattle received cash. Smoak is a .225 hitter in 1,928 Seattle at-bats, marginally better than Mario Mendoza’s .218. No player with Smoak’s career numbers has ended a career as more than a low journeyman. Beavan showed promise early, but it’s gone unfulfilled.

Dec. 2, 2010: INF Jose Lopez to Colorado for RHP Chaz Roe. A .266 hitter in Seattle and a 2006 All-Star, Lopez played parts of four seasons with four teams after leaving the Mariners, never batting higher than .249. Roe didn’t play for the Mariners and appeared in only 21 MLB games, all as a reliever for Arizona. Bottom line: A bag of popcorn for a used resin bag.

July 30, 2011: RHPs Doug Fister and David Pauley to Detroit for LHP Charlie Furbush and OF Casper Wells. A big deal at the time, now not so much. The trade has become Fister for Furbush. Now with the Nationals, Fister is 51-52, 3.48 as a starter since leaving Seattle, Furbursh 12-22, 4.26 as a short, sometimes effective, sometimes not, reliever for the Mariners. Pauley hasn’t pitched in the majors in two years.

July 31, 2011: LHP Erik Bedard and RHP Josh Fields to Boston for OF Trayvon Robinson and OF Chih-Hsien Chiang. Bedard has already pitched for four teams since leaving Seattle without much success (16-34), although he infamously blanked Seattle 4-0 June 6. The Mariners lost little, gained nothing.

Jan. 23, 2012: RHP Michael Pineda and RHP Jose Campos to the Yankees for C Jesus Montero, RHP Hector Noesi. A debacle, even though Pineda, due to legal and injury issues, has barely pitched for the Yankees. The Mariners vastly misjudged Montero’s ability to contribute at the major league level. Noesi reprised Horacio Ramirez before the Mariners shooed him out of town in April, but woke up to a nightmare July 6 when Noesi beat them 1-0.

July 23, 2012: OF Ichiro to the Yankees for RHPs Danny Farquhar and D.J. Mitchell. The 40-year-old Ichiro can still bring it – he had three hits against the Twins Sunday – although not with nearly the frequency that marked his time in Seattle. Farquhar is a major cog in a Seattle bullpen that ranks among the best in the American League.

July 30, 2012: RHP Brandon League to the Dodgers for OF Leon Landry and RHP Logan Bawcom: An All-Star closer in Seattle (2011), League has been serviceable for the Dodgers, but nothing special. Neither Landry nor Bawcom have played at the major league level.

Dec. 19, 2012:  LHP Jason Vargas to the Angels for 1B/DH Kendrys Morales. Morales hit 23 home runs and drove in 80 in his one year in Seattle, while Vargas, a winner of 36 games with the Mariners (2009-12) went 9-8, 4.02 in his one year with the Angels. Both have moved on, Vargas to Kansas City, Morales to Minnesota. Vargas is 8-4, 3.31 for the Royals this season. Although batting .229 at first pitch Wednesday, Morales drove in three runs in Minnesota’s 8-1 victory.

Dec. 13, 2013: RHP Carter Capps to Miami for OF/1B Logan Morrison: Morrison has become Seattle’s first baseman because Smoak failed. Morrison is batting .235, but that’s better than Smoak’s .204. Capps has appeared in only nine games for the Marlins.