Yankees left-hander Nestor Cortes has a flexor strain in his pitching elbow and was placed on the 15-day injured list in a blow to New York’s rotation heading into the playoffs. Cortes and the Yankees are still holding out hope he could return at some point in the postseason, but it didn’t sound likely. Cortes was scratched from his scheduled start Wednesday night against Baltimore and replaced by Marcus Stroman, with the Yankees one win from clinching the AL East title and a first-round playoff bye. Cortes had an MRI on Monday and was put on the IL retroactive to Sunday.