New York Yankees manager Aaron Boone walks to the dugout...

New York Yankees manager Aaron Boone walks to the dugout during the seventh inning against the New York Mets in an MLB baseball game at Yankee Stadium on Monday, Aug. 13, 2018. Credit: Kathleen Malone-Van Dyke

SEATTLE – If the Yankees do play in the American League wild-card game Oct. 3, Aaron Boone made it clear that their starting pitcher in that game is very much up in the air.

“I think that's decided over the final 22 games,” Boone said before Friday night’s game against the Mariners. “I’m sure we have three, four, five of them [candidates].”

Given Luis Severino’s second-half struggles, Boone’s comments were not a surprise, Severino  was 14-2 with a 2.31 ERA at the All-Star break, but cracks had begun to show. He allowed a combined seven runs in two starts before the break, the beginning of an 11-game stretch in which he has gone 4-5 with a 6.83 ERA.

As of now, J.A. Happ and Masahiro Tanaka, Friday night’s starter, would have to be considered the favorites to start the wild-card game.

“I think it comes down to who's pitching well, what does the matchup look like, where we are bullpen-wise,” Boone said. “I think these next few weeks will kind of tell us who that guy is.''

Didi's back

After missing 16 games because of a left heel contusion, Didi Gregorius was activated from the disabled list Friday but did not start.

“We’ll kind of ease Didi back in,” Boone said, referencing the fact that Gregorius did not play in any rehab games. “Hope to get him at some point [Friday night] and probably start him Saturday. Kind of build him back [up].”

Warren open to returning

 Adam Warren, dealt to the Mariners July 30 for international pool money, said he was “really surprised” and “disappointed” when he got the call from general manager Brian Cashman that he had been traded. But Warren, 31, a free-agent-to-be, said he isn't opposed to signing with the Yankees.

“I loved being a Yankee and I’ll always keep that option open if they want me back,” Warren said. “Definitely no hard feelings.”

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