In search of a much-needed victory Wednesday, the Mariners offered up another dud. Enduring their fifth consecutive loss and 12th in the past 17 games, Seattle squandered a brilliant effort from rookie starter Taijuan Walker and fell 1-0 to Mark Buehrle and the Blue Jays in Toronto.

The disappointment was compounded by the fact that an earlier loss by the Athletics, 5-4 to the Angels, breathed life into the playoff bid by Seattle. Cleveland also beat Kansas City 6-4, and pushed the Indians to 83-76, a half-game behind the Mariners at 83-75. The A’s and Royals are tied at 86-72 for the American League wild card spots with four to play.

The Mariners were shut out for the 19th time, which took a mere one hour, 59 minutes.

The Mariners walked away encouraged about one aspect: Walker, the team’s 2010 first round pick (43rd overall). He pitched the best game of his brief major league career. The right-hander held a Toronto squad that scored 24 runs off Seattle pitching in the first two games of the series to one run on four hits and a walk in a career-high eight innings.

It should have been better than that. In the eighth inning, Walker (2-3, 2.61 ERA) issued his only walk, a four-pitch pass to the light-hitting Munenori Kawasaki, a former Mariner. Walker recovered to strike out Anthony Gose swinging on an 88 mph changeup for the second out and his sixth strikeout. Walker then engineered a weak fly ball off the bat of Ryan Goins for what appeared to be the third out.

Unfortunately for the 22-year-old and the Mariners, it wasn’t. The lazy fly ball found hard turf when the trio of Austin Jackson, Robinson Cano and right fielder Logan Morrison couldn’t reach it. Jackson, playing regular depth, got a late jump on the ball, which was hit off the end of the bat. Cano peeled off his pursuit in the last moment, thinking Jackson had a play.

Instead, Kawasaki, benefiting from the ball’s high bounce off the hard surface, scored all the way from first, thanks to a good jump on the 3-2 pitch.

Trailing 1-0 in the ninth inning after succumbing to the dealings of Buehrle, Chris Taylor gave the M’s a chance with a lead-off single. It was the final pitch from the veteran left-hander. Buehrle (13-10, 3.39 ERA) was lifted by manager John Gibbons after allowing three hits and a walk in eight-plus frames. He struck out 10.

Seattle manager Lloyd McClendon sent out James Jones to pinch run for Taylor.  The speedy Jones immediately went to work attempting to steal. Jays reliever Aaron Sanchez was conscious of Jones’ large lead, and after one close pick-off attempt, nailed him on his second try. The pick-off eliminated any threat. Jackson and Dustin Ackley struck out and grounded out to end the game.

Disappointment could not be overstated for a Seattle squad that, despite a terrible September, still found itself in the race for a postseason berth.

The rookie’s first full season was interrupted by injury and poor command. The latter resulted in a month-long stint in Triple-A ,where he worked on pitching from the stretch to simplify his mechanics. After a stint in the bullpen, Walker has performed admirably filling in for the injured Roenis Elias, pitching to a 2.02 ERA over 13.2 innings.

Wednesday he showed the adjustment is working. He had excellent command of a fastball, changeup and curveball, thrown to all areas of the strike zone. His fastball reached 98 mph and was complemented by a 87-90 mph changeup with tremendous late movement. Of the four hits, none went for extra bases. The bloop off Goins’ bat advanced Toronto’s lone baserunner past first.

With four games remaining, Seattle must record a minimum of three wins and continue to get help to extend its season.

Notes

All three of Walker’s major league victories have come against the Houston Astros in eight career starts . . . Walker pitched 120.1 innings between the majors and minors in 2014 . . . Morrison made his seventh start in the outfield and saw his nine-game hitting streak come to an end.