OAKLAND -- A¡¯s manager Mark Kotsay has developed a formula for late-game situations with a lead this season by relying heavily on a trio of relievers. Heading into Friday night, though, he knew strategizing for such a situation would be a bit more complex.

A three-run lead against the Rangers after six innings presented a seventh-inning spot typically reserved for Domingo Acevedo. But with the right-hander among the league leaders in appearances -- and having pitched three times over the previous four days -- Kotsay had already planned to give him the night off.

With Acevedo unavailable, the ideal workaround plan was for starter Cole Irvin, who¡¯d limited Texas to two runs across the first six innings, to complete the seventh. That way, setup man Zach Jackson and closer Dany Jim¨¦nez could still line up for their usual roles with plenty of cushion. But once Irvin reached 93 pitches in the seventh on a one-out single allowed to Kole Calhoun, Kotsay opted for Justin Grimm as his first arm out of the bullpen.

Grimm, seldom-used in high-leverage scenarios this year, was thrust into a big spot and struggled. He retired just one of three batters faced, and by the time he walked off the mound as he was replaced by Jackson, Oakland¡¯s lead shrunk from three runs to one. After Jackson allowed a game-tying double to Adolis Garc¨ªa in the eighth, Jim¨¦nez surrendered three runs in the ninth, capping a rare off night from Oakland¡¯s normally capable back end of the bullpen in an 8-5 loss to Texas at the Coliseum.

¡°In terms of the bullpen, they¡¯ve done a great job all year,¡± Kotsay said. ¡°This isn¡¯t something that really happens. Our bullpen has come in and closed out games with leads. Not our normal night from the 'pen.¡±

Jackson entered the night having allowed just one earned run over his last nine outings. Meanwhile, Jim¨¦nez hadn¡¯t allowed a run in eight of his previous nine games. Of course, perfection for any bullpen over a full season is an impossible task. Coupled with the heavy usage of both relievers -- Jackson¡¯s 22 appearances are tied with Acevedo for second-most among American League relievers, while Jim¨¦nez was making his third appearance in the past four days -- an off night was bound to happen at some point.

¡°That¡¯s baseball,¡± Irvin said. ¡°As much as we¡¯d like to be on our best every day, we¡¯re not going to. I thought, offensively, we did enough to get the job done. It¡¯s just one of those nights where it didn¡¯t all click.¡±

Pitching himself into a jam in the ninth, Jim¨¦nez was one strike away from keeping the game tied heading to the bottom-half of the inning with the middle of Oakland¡¯s order due up. Instead, a two-strike single by pinch-hitting Andy Iba?ez that plated home a pair of runs was followed up with an RBI single from former A¡¯s star Marcus Semien.

Given his early success this year, entering Friday with just one earned run over 18 1/3 innings, the A¡¯s have strong reason to believe this could be just a minor blip on the radar for Jim¨¦nez.

The bullpen¡¯s inability to finish was not the lone culprit in this loss. The A¡¯s offense broke out for a five-run frame against Rangers starter Jon Gray in the third, ignited by Ram¨®n Laureano¡¯s RBI single and highlighted by back-to-back homers from Sean Murphy and Chad Pinder. But they were held hitless the rest of the way and the mood amongst A¡¯s hitters was one of frustration, feeling they let a stumbling pitcher in Gray off the hook.

¡°We need to hit better, starting with me,¡± Laureano said. ¡°The bullpen has been there a lot. As hitters, we¡¯re not there as much as they are. If we can be as they are, we will be a way better team.¡±