MESA, Ariz. -- Dontrelle Willis left the Reds' split-squad game against the Cubs after one-third of an inning with an injury sustained on a run-scoring play.

Willis was backing up the plate on Bobby Scales' two-run single and may have tripped on a bat in the process. He limped back toward the pitcher's mound and was taken out of the game before facing another batter.

"He just had a little roll over with his ankle, and we wanted to get him out of there and make sure he doesn't get hurt," bench coach Chris Speier said after managing the split-squad game in Mesa. "It's not bad. They'll know more tomorrow."

Willis, battling to make the club as a non-roster invitee, walked two and gave up two hits, allowing two runs. He had been on a roll entering the game, having pitched scoreless two-inning outings his last two times on the hill.

Willis will undergo further evaluation at the team's complex in Goodyear, Ari.

Bailey pleased with step forward

MESA, Ariz. -- Homer Bailey didn't hurt his chances to make the Reds' rotation on Saturday, but with a high pitch count that limited his innings, he didn't help himself as much as he might have.

Bailey threw 71 pitches over four innings, holding the Cubs to one run on six hits and two walks while striking out five in a 7-6 Reds win.

"The main thing with him was his inability to get ahead of the hitters," Reds bench coach Chris Speier said after managing the split squad in Mesa. "It cost him having to come out of the game. Other than that, his stuff was really good."

He gave up his one run when a one-out single by Marlon Byrd was followed by a double from Aramis Ramirez. Bailey was most severely victimized by Bobby Scales, who got two hits off Bailey from the seventh spot in the lineup, and Jim Adduci, who walked twice in the eight-hole.

"If you eliminate the two walks, that was probably the thing that upset me the most," Bailey said. "Other than the guys at the bottom of the order, I felt pretty good today."

Bailey is the front-runner in the race to win the fifth spot in the rotation, in part due to the fact that he is out of options and the Reds would likely lose him if he's not on their Opening Day roster. He struggled in his second start of the Cactus League, but he was able to escape jams and minimize damage in his third start on Saturday.

"We still have a couple weeks to go, so I need to build up some innings and build up some things," Bailey said. "I got behind in the count too much today, so I'll have to go back and fix that."

While his secondary pitches were sharp, the deep counts were an indication that fastball command remains the most important issue for Bailey to address.

"I threw some good sliders," Bailey said. "I had a couple strikeouts on splits. A couple strikeouts on that slider. Even though my curveball was down most of the time, I'd rather be there than be loopy and right down the middle. My biggest thing today was my fastball to my arm side wasn't really where it needs to be."