Two MRIs, two setbacks.

The Cubs got a double dose of unwanted news Tuesday as MRIs on pitcher Scott Baker and third baseman Ian Stewart revealed injuries that will keep them out for the foreseeable future.

Baker, who made his first Cactus League start Sunday against Oakland and threw 23 pitches, felt discomfort in his surgically repaired right elbow. He was not scheduled to start the season on the active roster, but the Cubs have suspended his throwing program, and they say they'll know more this weekend, when Baker sees team orthopedist Stephen Gryzlo.

Stewart, who injured his left quad a month ago, has additional fluid in the area, and the Cubs said he would open the season on the disabled list.

With Baker and Matt Garza (lat muscle) both on the shelf for Opening Day, the Cubs will go with a rotation of Jeff Samardzija, Edwin Jackson, Travis Wood, Scott Feldman and Carlos Villanueva.

"Right now, I'm choosing to be optimistic and hope for the best," said Baker, who signed a one-year, $5.5 million contract in the fall. He underwent Tommy John surgery last April 17 and missed the entire season with the Minnesota Twins.

"Obviously, any setback of any sort is not something that you like to hear," Baker said. "But I think we'll know more when Dr. Gryzlo gets down here and he can do a physical exam. MRIs are great, but you treat the patient. You don't treat the MRI."

As for Stewart, he has not had an official Cactus League at-bat. He played in a minor-league game last week, but could not go in another this past Sunday.

"I can't get through he running part," Stewart said. "That's really the last hurdle … I don't know if playing in the minor-league game the other day hurt it at all. There were a couple of checks-swings where I felt the muscle pull."