The Cubs put reliever Kerry Wood on the 15-day disabled list with right shoulder fatigue.
Ryan Dempster had an MRI on his right quad Friday and his start against the Reds on Sunday is questionable, a source familiar with the situation told ESPN Chicago's Bruce Levine.
Randy Wells will be recalled from Triple-A Iowa and get the start if Dempster cannot pitch.
The Cubs are recalling Scott Maine from Triple-A Iowa to take Wood's place.
Wood left the team Tuesday to get a cortisone shot in Chicago and missed the entire series against the Miami Marlins.
"I don't think anything out of the ordinary," Sveum said about Wood's rehab program. "So far the [cortisone] injection has helped a lot."
The Cubs did not bother giving Wood an MRI since he already has a tear in the right rotator cuff that he has pitched through since 2008. Wood's current shoulder discomfort dates back to spring training. He was held to just over five innings in Cactus League play.
"That's just baseball, but I hate to see Woody hurt," said Reds closer and former Cub Sean Marshall. "He is a great person and was also a wonderful teammate to me so it's tough to see him go through a little setback. I know he will be fine. He is in good shape. [This winter] was the best condition I ever saw him in."
Dempster is 0-1 with a 1.33 ERA in his first three starts.
ESPNChicago.com's Bruce Levine and Doug Padilla contributed to this report.