"I could if I wanted to," Showalter said. "Not saying I'm going to. Could. That part of it, he's not competing against the people up here [current Orioles starters]. He's competing to be good enough to compete against [Orioles opponents]."
Santana opted to stay in the organization and not exercise the opt-out clause in his contract, with the Orioles announcing on Monday that they had selected his contract -- adding him to the 40-man roster -- while the lefty continues to rehab. Santana is expected to make one rehab start at Double-A and then another at Triple-A and could be an option by mid-June.
"I don't think there will be anything difficult about it," Showalter said of finding room for Santana in the rotation. "I've been hinting around at going to six starters anyway. It's not a problem. Anytime there are good pitchers available, especially with his pedigree."
Brittany Ghiroli is a reporter for MLB.com. Read her blog, Britt's Bird Watch, and follow her on Facebook and Twitter @britt_ghiroli. This story was not subject to the approval of Major League Baseball or its clubs.