Nestor Cortes reportedly needs to undergo an MRI scan of his throwing arm as the Yankees battle for the AL East title

The New York Yankees are on the verge of winning the AL East despite receiving troubling news about one of their starting pitchers on Wednesday. Left-hander Nestor Cortes, Wednesday's scheduled starter, will undergo an MRI scan of his elbow, the YES Network reports. The team has not yet announced an official diagnosis.

Cortes, 29, leads the Yankees in starts (31) and innings pitched (174 1/3) and has posted a 3.77 ERA with strong underlying numbers (3.83 FIP, 3.65 xERA, etc.). New York used Cortes out of the bullpen two weeks ago — he threw 4 1/3 hitless innings to earn one save — in preparation for a possible relief role in the postseason. He was in the playoff plans either way.

Before the Cortes news, the Yankees were as healthy as they've been on the mound all season, with the only notable absence being injured setup man Jonathan Loáisiga. Before Cortes' injury, they had six starters for five rotation spots. Their rotation depth chart looks something like this right now:

1. RHP Gerrit Cole
2. LHP Carlos Rodon
3. RHP Luis Gil
4. RHP Clarke Schmidt
5. LHP Nestor Cortes (getting an MRI scan on my elbow on Wednesday)
6. RHP Marcus Stroman

Stroman was moved to the bullpen last week and hasn't pitched since Sept. 17. He's the obvious candidate to step in and start on Wednesday. Right-hander Cody Poteet is also expected to join the team in New York, according to the YES Network, though it's unclear if he'll be added to the active roster or placed on the taxi squad.

With 92-65, the Yankees have already secured a place in the postseasonand another win (or another Baltimore Orioles loss) secures the AL East title. The Yankees lost Tuesday's game against the O's (BAL 5, NY 3), but have two more games left in that series, plus a three-game series against the Pittsburgh Pirates this weekend.