Tomoyuki Sugano was slated to start Saturday night. Instead, the Colorado Rockies right-hander landed on the 15-day injured list due to back spasms.
Sugano was already dealing with a fingernail issue that pushed back his appearance a few days. His back acted up while playing catch, and the Rockies elected to place him on the injured list in a move retroactive to Wednesday.
"This should be very minimal," Rockies manager Warren Schaeffer said Saturday before his team's 6-4 loss to the San Francisco Giants. "I don't think it's a big deal."
Sugano is 8-4 with a 4.80 ERA in his first season with Colorado.
Left-hander Sean Sullivan (0-3, 8.87 ERA) was called up from Triple-A Albuquerque to start in place of Sugano and allowed six runs on 12 hits over 5⅔ innings. He struck out four in 105 pitches.
The Rockies also placed right-handed pitcher Seth Halvorsen (shoulder inflammation) on the 15-day injured list and selected the contract of two-time All-Star reliever Jordan Romano from Albuquerque.
Romano finished Saturday's game for Colorado, striking out two on 10 pitches in the ninth inning.
Romano was signed by Colorado to a minor league deal on May 6 after the right-hander was designated for assignment by the Los Angeles Angels in late April. He was 0-2 with 10.13 ERA with the Angels.
While with the Isotopes, Romano threw in nine games and had a 4.15 ERA with 10 strikeouts and zero walks. He is trying to recapture the form that led to back-to-back 36-save seasons with the Toronto Blue Jays in 2022 and 2023.
"There was a point there where he was the best big league closer in the game," Schaeffer said. "He's got pedigree. He knows what he's doing out there on a big league mound. It's awesome to have him.
"We signed him, sent him to the lab, gave him some time [at Triple-A]. He's been pitching well; his velocity is up. We're just super, super happy to have him and what he brings to a bullpen."
The Associated Press contributed to this report.