• Carlos Villanueva, projected as a swingman for the Cubs this season, will make his first Cactus League start on Wednesday when the Cubs play the Rockies.
Villanueva is not on the list of candidates for the fifth spot in the rotation.
"I think he could be used if needed to be," Renteria said. "We're still trying to see the rest of the guys we have. We're still going to let the spring play itself out."
Chris Rusin, James McDonald, and Tsuyoshi Wada are the pitchers the Cubs are considering for the one opening. Wada was roughed up by the Mets in Las Vegas on Saturday.
"It seems like he gets a little better and then takes a step back," Renteria said of the lefty. "He wants to compete, he wants to do well. He's very driven to do well. If he doesn't, he's disappointed. We hope he continues to go out there and keeps grinding and keeps trying to better himself and show us what he's got."
Wada has given up seven runs on 10 hits and five walks over 5 2/3 innings in three games. Renteria said the club is still finalizing the schedule and couldn't say whether Wada would get another start.
• Outfielder Casper Wells was sidelined with back spasms and listed as day to day. Outfielder Mitch Maier has a herniated disk and has yet to be cleared to play in a game. Both are non-roster invitees.