Whitley will undergo an MRI on his right elbow, Wallace Matthews of ESPN New York reports. Whitley struggled to record five outs Thursday, and was stuck with three runs on his ledger after Esmil Rogers allowed two inherited runs to score. The elbow injury is of more concern for New York, though Whitley's status won't be known until the MRI results come back. Chris Capuano (quad) could be an option to start Wednesday against the Nationals if Whitley is unable to go.