The Colorado Rockies placed rookie right-hander Victor Vodnik on the 15-day injured list Wednesday because of right biceps inflammation.
The move is retroactive to Monday. In a corresponding move, the Rockies selected the contract of right-hander Jeff Criswell from Triple-A Albuquerque.
Vodnik was loosening up to pitch in the ninth inning of Colorado's 3-1 victory at the Washington Nationals when he reported having right shoulder discomfort and did not enter the game.
"Victor has been going hard," Rockies manager Bud Black said Tuesday. "This is a rookie, and we've talked about the dog days of August. It's the first full season for Victor. It's not totally unexpected that he might have a little arm issue, so we're going to be a little cautious.
"To his credit, he said something as opposed to pitching through it."
Vodnik, 24, last pitched Sunday and earned his ninth save in a 3-2 home win over the San Diego Padres. He is 3-3 with a 4.04 ERA, 31 walks and 57 strikeouts in 64⅔ innings over 55 relief appearances.
He led the major leagues among rookie relievers going into Tuesday with his total innings pitched.
Vodnik, who made his major league debut on Sept. 9, 2023, is a career 4-3 with a 4.54 ERA over 61 relief appearances.
Criswell, 25, was 1-1 with a 6.24 ERA and 83 strikeouts in 57⅔ innings over 35 relief appearances with Albuquerque this season. He pitched a scoreless inning and allowed one hit in his major league debut as the Rockies lost to the Nationals 6-1 on Wednesday night.
Field Level Media and The Associated Press contributed to this report.