OAKLAND -- When drawing up the different possibilities to lose a game, the A’s don’t expect to lose many as a result of poor pitching from their top two bullpen arms, but that’s exactly what went down on Wednesday.

A feeling of deja vu struck the Coliseum after Matt Olson provided a late game-tying two-run homer against the Angels bullpen for a second straight game only to have his own bullpen struggle to keep the momentum alive, this time with closer Blake Treinen surrendering a pair of ninth-inning runs. The A’s kept fighting, rallying to tie it again against Angels closer Hansel Robles and force the game into extras, but a meltdown in the 11th by the usually dominant setup man Lou Trivino was far too much to overcome in a 12-7 loss.

“I don’t think there was a minute after Oly hit the home run that we didn’t think we were going to win,” A’s manager Bob Melvin said. “Pretty good position with some of our better relievers in the game, it just didn’t work out. It’s demoralizing when you tie the game, lose it, come right back and they score like that.”

• Box score

After preserving the tie in the 10th, the Angels unloaded on Trivino for a five-run 11th. The inning was exasperated by a rare error from Olson -- a Gold Glove first baseman -- who, after charging in to field a sacrifice bunt by Luis Rengifo bobbled the ball as he thought about trying to get the lead runner out at third before rushing a bad throw to Jurickson Profar at first. With runners at the corners and no outs at the time, the error allowed the go-ahead run to score and opened the floodgates. Trivino proceeded to walk in another run and surrendered a third on a single before getting pulled by Melvin.

Olson’s error didn’t help, but Trivino placed the blame on himself for the bad inning. The right-hander made a few self-inflicting mistakes, tying a season-high three walks and also hitting a batter. It was all about lack of command for Trivino as the Angels managed to plate the first two runs in the 11th without even recording a hit in the inning to that point.

“Our offense had a good game today and I didn’t really help anyone out there,” Trivino said. “I tried to minimize the damage. It is what it is, and I feel like I can learn from this.

“I didn’t show up today. The loss is on me.”

Showing fight

If the A’s are looking for positives from a gut-wrenching loss, they can find one in the fight they displayed to come back twice in the late innings. They could have moped around after seeing the Angels go back on top in the ninth, but instead, Mark Canha immediately welcomed Robles into the game with a leadoff homer in the bottom half, and Profar followed with a booming double off the wall in right-center before eventually coming around to score on Josh Phegley’s sacrifice fly for the tying run.

Canha’s solo shot was his ninth of the year and the A’s 35th in their past 15 games as the recent power surge continued.

“We’re always going to fight, we just didn’t have enough today,” Melvin said. “We’re never going to back down. This group just doesn’t know how.”

Opener struggles

The whole idea behind utilizing an opener to begin a game is to prevent your traditional starting pitcher from facing the opponent’s top of the lineup. But just as the A’s found out, if the opener himself is unsuccessful against the top of the order, the purpose is defeated.

Reliever Liam Hendriks found success in his first go as the opener earlier this month, but the strategy backfired on Wednesday as he dug the A’s in an early hole when he failed to keep the Angels off the board in the opening frame, pitching himself into a bases-loaded jam before allowing a two-out, two-run single to Cesar Puello.

After turning in a scoreless two innings the night before and entering the day unscored upon in his previous 11 outings, Hendriks had his career-high inning scoreless streak snapped at 14 2/3 innings.

“It didn’t work out,” Melvin said of the opener strategy. “Looked like his stuff was pretty good, but not as good as last night, and they get a big two-RBI hit.”

Hendriks would have been justified in chalking it up to fatigue as he threw 33 pitches on Wednesday after throwing the same amount the night before, but the right-hander refused to use that excuse. He was approached about the possibility after Tuesday’s game, and told A’s coaches he was ready to pitch for a second day in a row.

“I felt fine, I just wasn’t finishing pitches,” Hendriks said. “They laid off some pitches and hit the ones I left off the zone. It’s the problem sometimes with opening. I wasn’t on it today and it showed. It was unacceptable.”

Astros on deck

After dropping two of three to the Angels, the A’s welcome the Astros on Friday for the start of a three-game series. It’s only May, but given their current position in the AL West standings -- second place and eight games back of Houston -- the A’s know the type of impact a series like this can have down the road.

“We’re in a position where we need to make every series important,” Hendriks said. “When you take your foot off the gas, it spells trouble. We’re facing a team that is above us in the standings and every game counts. Maybe these three games are indicative of where we finish in the division.”