"We were skipping him a start for sure, and that would have gone until the last day of his DL if we hadn't put him on the DL," Melvin said. "So it makes sense to put him on the DL, get him back, throw [a] significant side and get a better read of where he's at.
"I know he felt a lot better yesterday, and hopefully that's the case leading up. But based on one or two days, it felt like it was the right thing to do. That's the reason for that."
Manaea left Wednesday's start against the Angels after two innings with shoulder stiffness, but there was a chance the 25-year-old could avoid joining the injured list. In five starts, he's 1-2 with a 5.18 ERA.
Oakland was short a pitcher on Sunday in the finale of a three-game series with the Astros at Minute Maid Park. The A's will make roster moves once the team gets to Minnesota. After an off-day on Monday, Oakland plays the Twins in a three-game series starting on Tuesday.
Sonny Gray will make his 2017 debut in the opener. Kendall Graveman is scheduled to start on Wednesday, and Melvin announced on Sunday that Jharel Cotton will start on Thursday.
Davis, who has been out with a left hamstring strain, ran the bases on Sunday and the center fielder is likely to be cleared to play against the Twins.
"Rajai Davis ran today, and he feels good," Melvin said. "So there's a good chance we take him off the DL on Tuesday as well."
Richard Dean is a contributor to MLB.com based in Houston.