The New York Mets have stuck with Edwin Diaz for months, but the reliever may be losing his grip on his role as the club's closer.

Diaz has a 5.44 ERA.

Mickey Callaway said Sunday that the Mets "have to be open-minded" about whom to use in the ninth inning of close games.

"I don't think we can lock ourselves in to one thing," Callaway said. "Moving forward, it's just something that we're going to do whatever we can to win a game that night. I don't think we can lock ourselves in to one thing."