DETROIT -- Offense? The A’s had plenty. Good vibes? Thanks to the return of clubhouse favorite Khris Davis, optimism ran high, too.

What Oakland did not have on Wednesday night was a way to plug a leaky bullpen during an 8-6 loss to the Tigers at Comerica Park.

“It’s something you always want to do, get out to a lead, and … tonight didn’t go our way,” leadoff hitter Josh Harrison said. “At the end of the day, as long as we’re having good at-bats one through nine … I don’t want to say it makes the job much easier [to go ahead early] because you’ve still got to play 27 outs, but it’s all about getting to that pitcher and trying to get to the bullpen.”

Was the defeat the fault of the A's relief corps? Not entirely. The arms have been called to service fairly often since staff ace Chris Bassitt’s frightening injury and resulting facial surgery after being struck by a line drive on Aug. 17. Overtaxing the bullpen is a dangerous game, with shorter rest between outings and longer outings themselves, but manager Bob Melvin and his coaching staff have often had no choice.

On Wednesday, the A’s watched leads of 1-0, 3-1 and 6-3 wither away in Detroit. Starter James Kaprielian didn’t have his best stuff, allowing four earned runs on four hits and three walks over four-plus innings, necessitating another lengthy stint from the bullpen.

While the 'pen has performed admirably under the circumstances, it has also had to endure a spate of inefficiency from the starting staff. In both games thus far in Detroit, the starter (first Cole Irvin and then Kaprielian) failed to make it through five innings.

Akil Baddoo’s homer to lead off the fifth knocked Kaprielian from the contest, sending in Yusmeiro Petit, the first of a four-man wave of relievers to the mound for backup. However, the lead quickly evaporated, as Detroit scored seven of its runs in its final five innings.

“Physically, I feel fine, I just didn’t have it today,” Kaprielian said. “Obviously extremely frustrated, and to be frank, I haven’t had a good outing the second half of the season, so … I need to figure it out and do a better job of it.”

It’s a troubling set of circumstances as the A’s attempt to improve their spot in the postseason race. Wednesday's defeat dropped Oakland to two games behind the Red Sox for the second AL Wild Card spot and kept the club five back of Houston, which lost its game to Seattle.

The A's need to soon strike a balance between both ends of the pitching staff, lest they either fall out of postseason contention entirely or sputter into October with an overworked stable of arms.

Taking over for Kaprielian, Petit served up a solo homer to Harold Castro in his two innings. A.J. Puk followed -- one night after he worked a scoreless ninth -- and failed to register an out, permitting another pair of runs on two hits and a walk. Puk’s second run allowed came after he’d gotten the hook, when Miguel Cabrera singled off Jake Diekman to put Detroit ahead for good.

The Tigers tacked on an insurance run off Daulton Jeffries in the eighth.

Offensively, the A's stayed warm at the plate, though they didn't score after the fifth inning (as Detroit began its comeback). Matt Olson continued his MVP-caliber campaign with a three-RBI performance, Jed Lowrie plated two on a pair of doubles, Starling Marte crushed a booming homer and Harrison went 3-for-5 with a double from the leadoff spot.

Olson, in particular, was impressive, providing a lot of the pep that got the Oakland bench rocking, starting with a first-inning sacrifice fly that plated Harrison for the A's first run.

After going down in order the next two frames while the Tigers evened the score, Oakland moved ahead in the fourth, 3-1, only to enter the fifth tied once again after Cabrera clubbed his 502nd career home run off Kaprielian.

Olson didn’t shy away from the challenge, tagging a two-run double beyond center fielder Derek Hill’s running leap at 109 mph to put the A’s back in front. Lowrie drove him in with a single that capped the A's night on offense.

“Usually, when we score six runs, we win the game,” Melvin said. “So, it is what it is. [The Tigers] fought back, they scored runs after the fourth, and we just couldn’t hold them down, unfortunately.”

The A’s collected 10 hits in the loss -- the second consecutive game during which they tallied double digits -- with half of those going for extra bases.