Brayan Bello's frustration boiled over in a moment that caught everyone's attention during Wednesday's game against the Blue Jays. The Red Sox starter was visibly upset, shaking his head repeatedly as interim manager Chad Tracy approached the mound to pull him with two outs in the fourth inning at Rogers Centre.

Boston went on to lose 8-1, but the real story was Bello's emotional reaction. Trailing 3-1 and at just 63 pitches, the 26-year-old right-hander had walked No. 9 hitter Brandon Valenzuela before Tracy and pitching coach Andrew Bailey decided together to bring in reliever Greg Weissert.

Back in the dugout, Bello didn't hide his feelings. He paced back and forth, talked to himself, and continued shaking his head. When Weissert allowed a two-run homer that made it 5-1, Bello slammed his fist on the railing in frustration.

"Obviously, I was upset," Bello said through translator Carlos Villoria Benítez. "I haven't been able to pitch well in the past few starts. I haven't been able to pitch deep into the games. That's what I want. And today it went that way as well. So obviously I was upset to come out of the game."

This marked the fourth time in six starts this season that Bello pitched four or fewer innings, a troubling pattern for a pitcher the Red Sox are counting on. When asked if he thought he should have stayed in, Bello answered simply: "Yes." But he emphasized his frustration was directed at his own performance, not the decision.

"I haven't been able to pitch five innings in a few games, so I was very upset with myself," he said.

Pitching coach Andrew Bailey defended Bello's reaction, noting that passion is part of the game. "I've gotta talk to Trace on that, but I think he understands that it's the heat of the moment, and we've gotta operate with some grace," Bailey said. "These guys are human beings. They want to win and they want to compete. I don't think there's any malice behind his frustrations."

Manager Chad Tracy, who hasn't yet spoken with Bello about the incident, wasn't concerned. "Most pitchers I know don't like to come out in the fourth inning, so that's OK," Tracy said.

With his ERA now at 9.00, Bello knows he needs to find his rhythm—and fast. For a pitcher who showed so much promise, this stretch has been a tough test of his mental and physical game.