DETROIT -- San Diego Padres left-hander MacKenzie Gore exited a 12-4 loss to the Detroit Tigers on Monday night with elbow soreness.
Gore, a 23-year-old recently shifted to the bullpen, relieved starter Sean Manaea during the fourth inning. He threw 35 pitches and recorded four outs before walking off the field with a trainer.
"His [velocity] was down some, we haven't see the [velocity] great for awhile now," San Diego manager Bob Melvin said. "It became evident in that inning, so we went out there, and felt it was good to get him out of there."
Gore averaged 92.7 mph on his fastball against the Tigers, down more than 2 mph from his season average. He was charged with two runs, both on a homer by Jeimer Candelario.
"He'll see our doctors when we get home," Melvin said. "And we'll treat him in the next couple of days, and see where it goes."
A first-round draft pick in 2017, Gore had ranked among the game's top pitching prospects since but didn't debut in the majors until this season. He was exceptional early in the season, going 4-1 with a 1.50 ERA in his first nine games, including eight starts.
This was his second straight outing out of the bullpen after San Diego transitioned from a six-man rotation to a five-man staff. Gore's 70 innings pitched this season are already 19⅔ more than he threw in 2021, and he was on pace to far exceed his career high in the minors of 101 innings.
Manaea struggled against the Tigers, taking the loss after pitching just 3⅓ innings with four earned runs and four strikeouts.
The Associated Press contributed to this report.