For now, Jimenez -- who allowed six earned runs over four innings on Monday and has a 7.17 ERA -- will remain part of the rotation.
"If [moving him to the bullpen] was the case, he couldn't pitch there for two or three days at least, maybe four," Showalter said. "That decision, one way or another, hasn't been made."
Should Jimenez not be tabbed on Sunday, the O's could use Alec Asher, who has been terrific in relief and was used as a spot starter earlier this year. That would take a key arm out of the bullpen, however.
"There's different challenges in our bullpen with Zach [Britton] out," Showalter said. "You need to have some versatility down there, and some guys that can pitch physically more than once every four days down there. It doesn't work."
• The O's daily roster carousel kept spinning Tuesday, as the club sent Stefan Crichton back to Triple-A Norfolk and recalled Jayson Aquino. Showalter said Logan Verrett is still on paternity leave and therefore not an option, given that fact and how long he's gone without pitching.
• Outfielder Michael Bourn is not with Norfolk's bullpen, as the outfielder is expected to exercise the opt-out in his contract.
Brittany Ghiroli has covered the Orioles for MLB.com since 2010. Read her blog, Britt's Bird Watch, follow her on Facebook and Twitter @britt_ghiroli, and listen to her podcast. This story was not subject to the approval of Major League Baseball or its clubs.