BOSTON -- Garrett Whitlock's latest audition to become a permanent member of the starting rotation for the Red Sox? Perfect. Well, almost perfect.

Whitlock created a special feeling in the early innings at Fenway Park on Wednesday night when he set down the first 13 Angels hitters he faced, throwing just 63 pitches in the process.

But it wound up being a most imperfect night for the Red Sox as the bullpen couldn’t hold the lead one strike away from victory in the ninth. Then, there was a six-run implosion in the 10th inning in what wound up a difficult 10-5 loss.

The night started with one obvious storyline: Whitlock (five innings, two runs, no walks, nine strikeouts on 78 pitches) should be starting.

Then it shifted gears to another one: The struggling bullpen might need Whitlock back.

Manager Alex Cora will continue to weigh his options for a dynamic righty who has a 1.80 ERA in his first 53 MLB appearances, the last three of which have been solid starts.

Intertwined with that is that Cora is trying to figure out how to maximize a bullpen that has been a catalyst in his team being 0-5 in extra innings so far this season.

“It all depends how you see it. [Whitlock] gave us 15 outs,” said Cora. “Everybody has to do their job at the end of the day. We cannot rely on one guy. We saw what he did last year, what he did early on. He’s done an amazing job starting for us, too. He’s not going to pitch every day. The other guys have to step up, and so far it’s been inconsistent.”

When Xander Bogaerts hammered a towering shot over everything in left with one out in the eighth to put his team in front, the Sox were just three outs from taking a series win from the Angels with a chance to sweep them on Thursday afternoon.

Then it was down to one out away, though reliever Hansel Robles muddied the waters by walking the imposing Mike Trout-Shohei Ohtani duo.

Rather than letting Robles navigate out of that jam, Cora went to Jake Diekman for a lefty-lefty matchup with Jared Walsh. That didn’t end well for the Red Sox. Walsh worked a nine-pitch at-bat, which included seven straight sliders -- the last of which was belted into right field for a game-tying single.

It was the fourth time this season the Red Sox (10-15) have blown a save from the ninth inning on.

“We work so hard to get certain matchups and try to get 27 outs,” said Cora. “We keep the ball in the ballpark, and then in the end we walked a lot of people. We had the right matchups for the 27 outs and Walsh put a good at-bat, got a base hit and after that we didn’t execute pitches.”

The 10th inning is what really stung the Sox. With the automatic runner on second and two outs, Taylor Ward mashed a 3-1 fastball (94.5 mph) from Matt Barnes for a two-run homer.

One thing Cora would like is to have an established closer. He was hoping it could be Barnes, who was an All-Star in that role in the first half of last season before dipping significantly from August on.

With his latest mishap, Barnes, whose velocity has diminished significantly from last year, saw his ERA swell to 8.64.

“I’ve been terrible,” said Barnes. “Let’s just call a spade a spade. So I have to figure my [stuff] out.”

While there have been a few times this season that Cora has mixed and matched his bullpen to pull out tight wins, there have been too many other occasions when the battle plan has fallen apart due to untimely misfires.

“You guys know I like structure,” said Cora. “We tried the whole ace reliever in [the first half of] 2019. It’s different than this, of course. The three lefties gives us an advantage on certain days. But I think it’s one of those where we would love somebody to step up and be consistent to throw strikes, go through three batters and turn the page. That’d be great so we could actually set up the sixth, the seventh, the eighth. But so far, we’ve been up and down with this.”

Given that trade season is probably another month or two away for chief baseball officer Chaim Bloom, what can Cora do now?

“Trusting the players we have, the talent we have, somebody will step up,” he said.

One pitcher who has done that over and over for the Red Sox is Whitlock.

“Whitlock is one of the best arms I've seen in a while,” said Angels manager Joe Maddon.

Wednesday should have been about Whitlock’s sparkling performance. Instead, it is about how best to utilize him.

“I’m not worried about it,” Whitlock said. “Whenever they tell me to pitch is when I’ll pitch, whether it be the first inning or what. Whenever they tell me to go, I’ll go.”