OAKLAND -- For most of this 2021 campaign, the A’s bullpen had established a strong ability to nail down close games. Now, at a critical juncture in the season, those reliable relief arms have begun to falter.

For the second time in three days, Lou Trivino was unable to hold a one-run lead as he surrendered another back-breaking homer in the ninth inning. Monday's 5-3 loss at the Coliseum marked the third game in a row in which the A’s bullpen allowed a late lead to disappear.

The loss bumped the A’s out of their hold on the second American League Wild Card spot, as they ended the night a full game behind Boston.

The A’s had a one-run lead entering the ninth after Matt Olson’s 32nd homer of the year -- a tie-breaking solo shot in the sixth. Trivino was in search of a bounce-back after his blown save on Saturday afternoon. But just three pitches into his outing, he issued a game-tying solo blast to Ty France.

Despite following up the homer by allowing back-to-back hits, Trivino still had a chance to at least keep the game tied. Getting to two outs with strikeouts of Jarred Kelenic and Cal Raleigh, Trivino was pulled after giving up a go-ahead two-run single to Jake Bauers.

Prior to Saturday’s blown save against the Giants, Trivino had converted 14 consecutive save opportunities dating back to June 5, with an ERA of 0.84 over that stretch. Now having allowed five runs between his last two appearances, Trivino’s ERA has risen from 1.72 to 2.43.

So what's changed for Trivino as of late? There was some reason for concern in Saturday’s outing, as he was pitching a third day in a row for the first time this season. On Monday, though, A’s manager Bob Melvin said the "stuff" was better than last time, with Trivino’s fastball maxing out at 97.1 mph.

“He just gave up a home run last time, and this time leads off with a homer,” Melvin said. “France is having a really good year. Then he had a chance to get out of it, just couldn’t get the third strike across. He just has had tough back-to-back games.”

A’s catcher Yan Gomes also liked what he was seeing from the A’s closer, stuff-wise.

“I think we’re gonna definitely take a look back [at the film],” Gomes said. “But his stuff is there. Everything looks really good. Right now, it just seems like unfortunate luck, until we can figure something out.”

The A’s bullpen, which entered the day with just 13 losses on the season, has now been charged with a loss in three straight games for the first time this year.

Earlier in the year, Melvin was splitting closer duties between Trivino and left-hander Jake Diekman based on matchups. Trivino eventually seized the full-time closing duties with his solid run up until these last few games.

Asked whether he might consider revisiting a closer-by-committee scenario, whether it be with Diekman or another reliever, Melvin said, “[Trivino] is not gonna be able to pitch [Tuesday]. The workload, he was going to be off today or tomorrow. We were trying to break it up between all our [late-inning] guys in these next two days. I won’t have him available tomorrow. We’ll get through the off-day [on Wednesday] and we’ll see where we’re at.”

Possibly joining Trivino as unavailable for Tuesday could be Matt Chapman, who was scratched from Monday’s lineup with a left foot contusion. Melvin does not consider the injury to be too severe, though he did say the third baseman might not return until Thursday, when the club begins a crucial four-game series with the Yankees at the Coliseum.

“Chap was having a little tough time hitting and moving side to side,” Melvin said. “We tried to get him ready today, but he just couldn’t do it. Once he tried to hit in the cage, it was evident he wouldn’t be able to go. Hopefully, if it’s not tomorrow, we get through the off-day and [will see if] he’s better after that.”