Hellickson added: "It's something that if we were still in [playoff contention], it's something I could treat and go out there and pitch. But it's probably not the smartest thing to do that."
O's right-hander Dylan Bundy strained his left hamstring warming up and was a late scratch on Sunday. He also is expected to be shut down.
Hellickson was expected to bolster the O's rotation after being acquired in a trade with the Phillies at the non-waiver Trade Deadline. But Hellickson is 2-6 with a 6.97 ERA in 10 starts with Baltimore after going 6-5 with a 4.73 ERA with Philadelphia.
"It's definitely been an inconsistent two months," Hellickson said. "For some reason, I had a lot of big innings this year."
• Outfielder Adam Jones (leg soreness) and shortstop Tim Beckham (strained hamstring) were again held out of the O's starting lineup.
• Showalter tabbed left-hander Wade Miley to start Friday's series opener against the Rays at Tropicana Field. In 31 starts, Miley is 8-14 with a 5.52 ERA.
Bob Cohn is a contributor to MLB.com based in Pittsburgh. This story was not subject to the approval of Major League Baseball or its clubs.