CLEVELAND -- The Reds are down another starting pitcher after they placed rookie left-hander Amir Garrett on the 10-day disabled list with right hip inflammation.
Taking the roster spot for Garrett is right-hander Jake Buchanan, whom the Reds claimed off of waivers from the Cubs. To clear a spot on the 40-man roster, Cincinnati designated first baseman Peter O'Brien for assignment.
Garrett has a 6.00 ERA in eight starts, in part because his last two outings have been poor. On Tuesday against the Indians, he allowed seven earned runs on seven hits with one walk over five innings for a no-decision in an 8-7 Reds loss. Before that, he gave up six runs in four frames to the Cubs.
It appears that the 25-year-old Garrett was bothered already by the hip during Tuesday's game.
"I think it was exacerbated during the start," Reds manager Bryan Price said. "It wasn't a big deal, initially, because we didn't know about it. He said it had been about 7-10 days earlier that he first experienced it. I don't know if that was in his short two-inning outing in Louisville or somewhere in the aftermath. I don't think it was anything that was a cause for concern."
Garrett, who did not travel with the club, was examined by team medical director Dr. Tim Kremchek and underwent tests that included a MRI.
"The best-case scenario is he misses those 10 days of DL time and is ready to go right immediately following that," Price said. "The intention is to keep him from putting a lot of weight on his hip as he goes through the initial days of rehab. Then we'll get him back in the mix and be able to throw bullpens, which would be an essential part before we agree to get him back in the rotation."
Asher Wojciechowski or Buchanan were originally in mind to replace Garrett for the next turn in the rotation, which was supposed to be on Sunday at Philadelphia. However, with a rainout on Thursday, everyone is moving back a day and the Reds no longer need a starter against the Phillies. But someone will be needed to start on Tuesday during the next series at Toronto.

Buchanan, 27, has a 3.75 ERA in 24 games, including three starts, over parts of three seasons in the Majors with the Astros and Cubs. He last pitched in the big leagues for Chicago on Sept. 30, 2016, and defeated the Reds with five scoreless innings.
This season at Triple-A Iowa, Buchanan went 2-2 with a 4.75 ERA and a 1.63 WHIP in eight starts.
Worth noting
• Lefty reliever Tony Cingrani (right oblique) is scheduled to throw a simulated game on Friday with Class A Dayton. If Cingrani has no issues, a rehab assignment in the Minors will be slated.