Cubs manager Lou Piniella said Zambrano would be "stretched out" so he can be switched from short to long relief. Could that move signal his eventual return to the rotation?
"[Piniella] told me today there may be a chance I'll go back to the rotation," Zambrano said. "We'll see how everything works out in the next few days for me."
Since joining the bullpen on April 24, Zambrano has pitched in eight games and has a 6.23 ERA. When asked if Zambrano was headed back to the rotation, Piniella didn't offer a timetable.
"Probably down the road if need be," he said. "We thought the outcome would be a little different. He's not comfortable in the bullpen pitching short. We're going to use him in a different role, build up some stamina, build up his arm. That's what we're going to do."
Zambrano, a $91.5 million former All-Star, willl be available to pitch in long relief in Tuesday's game with the Colorado Rockies.
"Tomorrow will be a big day in the bullpen for me. I might throw 40 or 45 pitches. A lot of it will depend on how [starter Carlos] Silva pitches tomorrow. If he throws eight innings tomorrow, there is nothing I can do. That's his job. I'll have to back it up for the next day in Philadelphia."
Zambrano was asked if he's happy about the possibility of going back into the rotation.
"Yes, as long as this team is happy, I'm happy," Zambrano said. "The boss wants me to close games, I'll close games, if the boss wants me to be a starter again, I'll be a starter again. It's up to them, their choice."
Zambrano wasn't sure how long it would take to rebuild his arm strength.
"It all depends how I feel tomorrow. If I pitch tomorrow or the next day, we'll go from there. They told me tomorrow I'd possibly pitch two or three innings."
Bruce Levine covers baseball for ESPNChicago.com. Information from The Associated Press contributed to this report.