ST. PETERSBURG, Fla. -- The New York Yankees' starting rotation recently lost Nathan Eovaldi, its biggest winner, to an elbow injury. Now, with 18 games left in their chase for a playoff spot, they also will be without Ivan Nova.

But Nova's absence is not so much a loss as a demotion. Yankees manager Joe Girardi said the right-hander, who has been inconsistent since returning from Tommy John surgery in June, would be replaced in the rotation by Adam Warren. Nova will work out of the bullpen beginning with this weekend's three-game series against the Mets at Citi Field.

The Yankees trail the Toronto Blue Jays by three games in the AL East and have a 2½-game lead in the race to host the AL wild-card playoff game.

"We're trying to get the guys who are throwing the best right now,” Girardi said.

Ivan Nova is moving to the Yankees' bullpen after a string of ineffective starts. AP Photo/Kathy Kmonicek

Nova (6-8, 5.11 ERA) has been erratic since returning to the Yankees on June 24 and most recently failed to get out of the second inning in a crucial game Saturday against the Blue Jays in the second game of a doubleheader at Yankee Stadium. Nova allowed six earned runs on seven hits, including a two-run homer to Cliff Pennington, in 1⅔ innings. He has lost five of his past seven decisions.

Girardi said he thought Nova's struggles were related to the inconsistency that often plagues pitchers in their first season following Tommy John surgery.

"They say the last thing that comes is the command,” Girardi said. "His curveball at times has not been as sharp as we’ve seen it in the past.”

The news about Nova only came to light after Girardi announced his rotation for the Mets series -- Masahiro Tanaka on Friday, Michael Pineda on Saturday and CC Sabathia on Sunday -- which made it obvious that Nova's turn was being skipped.

"We have not made any decisions right now on when he'll pitch again,” Girardi said. "I'm not saying that he won't start another game, but over the weekend he'll be in the bullpen.”

Girardi said he informed Nova of his decision before Wednesday night's series finale against the Tampa Bay Rays at Tropicana Field.

"Most starters want to start, and I understand that,” Girardi said. "But we need his help in our bullpen now.”

Nova was not available for comment before the game.