PITTSBURGH -- All things considered, this day could’ve been worse.

Mitch Keller was removed from Tuesday’s 5-3 loss to the Red Sox at PNC Park with right shoulder fatigue after allowing five runs (four earned) in two innings. The outing was, by far, his shortest of the season, and one filled with causes for concern. His velocity was low, his command was erratic and his pace lacked fervor. Following the game, reassurance was provided.

“Never any indication of pain, no,” said manager Derek Shelton. “It’s more just fatigue. He felt tired in his shoulder. I think the good thing is there is no pain.”

For a moment, though, there was reason to believe something was amiss. The 26-year-old was off from the jump. His first pitch of the night, a sinker, clocked in at 90.8 mph. For comparison, Keller’s average sinker is 94.5 mph.

Keller would throw 46 pitches across two innings. His four-seam fastball was 3.2 mph slower than average. His slider and curveball were 3.8 and 4.8 mph lower than the mean. Only one pitch registered at 94 mph.

Velocity wasn’t the only attribute missing: Keller’s command was erratic. Several of his misses were uncompetitive. He left a fair share of breaking balls in the middle of the zone, and the Red Sox didn’t miss. Keller allowed the first six batters he faced to reach base. By the end of the first inning, Boston had scored four runs.

“What really stood out was the breaking ball,” Shelton said. “Just did not think it was as sharp. The curveball really looked like it got really big. We’ve seen his breaking ball be really tight.”

Said Keller: “I feel like everybody in the building who was watching knew that my velo was a little bit down and I was hanging sliders. Usually if those sliders are down and away they're ground balls, but they were up in the zone, so got hit a little bit harder for drives in the gap and lost some long outs.”

In addition to the lack of command and velocity, Shelton observed that Keller did not have his usual tempo, his usual aggression. When Keller is right, he stays in attack mode. On Tuesday, Keller’s pace was unusually slow. With these factors in mind, Shelton paid his starter a visit.

In the middle of the second inning, Shelton and assistant athletic trainer Tony Leo met Keller after he walked J.D. Martinez on four pitches, none of which were particularly close. Leo and Shelton asked Keller how he was feeling. Keller said he felt healthy and that he wanted to finish the inning. The conference concluded, Keller recorded the final out and his night was over.

“I'm frustrated, honestly. Just frustrated,” Keller said. “Nobody wants to give up runs. Obviously I had a really good thing going. Not saying that it's ended, but it just sucks to give up four in the first. You never want that to happen.”

With Keller exiting the ballgame after two innings, the Pirates were thrust into an unplanned bullpen game. They needed to cover seven innings, and those seven innings were brilliantly covered.

Chase De Jong pitched four scoreless innings of nearly perfect ball, the only blemish on his résumé being a harmless walk. Austin Brice blanked the Red Sox in the seventh and eighth. Manny Bañuelos threw a scoreless frame in the ninth. All in all, the trio didn't allow a hit across seven combined innings. No one knew at the time, but in doing so, that triumvirate made history.

According to Elias Sports Bureau, this was the first time since 1893 (the year that the mound distance was set to 60’6”) that the Pirates’ bullpen didn’t allow a hit in an outing where they pitched seven or more innings. An odd accomplishment, but one that De Jong was proud to be part of, regardless. 

“As soon as the starter comes out of the game, whether it be early or we’ve got to cover the last one, we take it to heart,” De Jong said. “Those are our innings. We cover those innings and try to do it as best we can.”

Now, the waiting game. Keller’s status for his next start is currently unclear. In Keller’s mind, however, there’s nothing to doubt. 

“I know I'm going to feel fine because I feel fine right now,” Keller said. “It's just one of those days, I guess.”