CINCINNATI -- Luke Weaver was probably going into the Reds' rotation in Connor Overton's place after his rehab assignment ends, but the move became a lock when Overton complained of a sore elbow after leaving Friday's start. 

The Reds signed Weaver, the 29-year-old right-hander, in January for $2 million for rotation depth. He strained his elbow in Spring Training. He made two rehab starts at Louisville, going four innings in the first game and five in the second. He allowed three runs on three hits, struck out nine and walked four over nine innings.

"There's a lot to like about Luke," Reds manager David Bell said. "He has a lot of experience having success in this league. He really likes being here, enjoys working with [Reds pitching coach Derek Johnson] and feels like he can become a better pitcher than he has ever been to this point. He has a lot of years [in MLB], but he's still young."

Weaver broke into the Majors at 22. As Bell said, Weaver's had success. He was 7-2 with a 3.88 ERA as a 23-year-old. But he's had some tough times at well. He was 1-1 with a 6.56 ERA last year.

Overall, Weaver is 24-36 with a 4.79 ERA in 115 big league games (81 starts).

Overton struggled in all three starts for the Reds. He was 0-1 with an 11.45 ERA. He told the team about the elbow issue after allowing five runs in three innings in Friday's 8-3 loss to the Phillies, and the club placed him on the 15-day injured list Saturday.

"He knew something was off while he was pitching last night, but we didn't know for sure what it was," Bell said. "We did get to the bottom of it."

RHP Casey Legumina took Overton's roster spot. Legumina was obtained in the Kyle Farmer trade with Minnesota. He went 5 2/3 innings for Triple-A Louisville. He allowed a run on six hits, walked none and struck out five.

"What stands out about Casey the most is that he doesn't show any fear," Bell said. "He's really good about trusting himself. His stuff is really good. He wants to be in every situation and is not intimidated by anything.

"The timing is right for Casey to make his debut and potentially be a big part of the bullpen."