What should the Yankees do about the rotation with Tanaka on the DL?

If you haven't already heard, Masahiro Tanaka has been placed on the 15-day disabled list with what the Yankees are calling a "very mild right forearm strain" along with tendinitis in his right wrist. Thankfully, an MRI on his UCL tear showed that it looks the same as it did the last time they checked it out, and Tanaka has said that he doesn't think his current pain is related to his elbow. According to Tanaka, he threw a bullpen session on Sunday which was fine, woke up Monday with a little pain in his wrist, thought it would be okay, but when he still felt it yesterday, he reported it to the team. The plan is to shut him down completely for seven days, and then build him back up. Brian Cashman estimated that Tanaka could be on the DL for as long as a month, but that's assuming that he doesn't experience any setbacks. In the meantime, what should the Yankees do about the rotation?

As luck would have it, Chase Whitley was called up yesterday to take Tanaka's start and push back the entire rotation a day. Tanaka would have started today, but now the Yankees are going to have everyone pitch on normal rest, which means that Michael Pineda would pitch today. Unfortunately, the entire point of calling Whitley up was to give everyone extra rest during this stretch where the Yankees play 30 games in 31 days. The good thing is that Whitley can easily jump right into Tanaka's spot in the rotation for the next month, but now no one gets the extra rest that the Yankees were looking for.

The Yankees could still add an extra starter to give the rotation some rest, but choices are getting thin at this point. Now that Whitley is part of the rotation, Bryan Mitchell is the only starter left on the 40-man roster. He was bounced around between the majors and Triple-A a lot last season, but didn't get a chance to play for the team until September. During his limited opportunity, he made one start, pitched 11 innings, and gave up just three runs. Mitchell had an outside chance of making the team during spring training, but he didn't pitch all that well, and Whitley looked better between the two of them. However, Mitchell currently has a 2.11 ERA and 2.72 FIP through four starts in Triple-A. Of the other pitchers who could potentially help the rotation, Chris Capuano and Ivan Nova are both still on the DL. Capuano is expected to return in mid-May, while Nova may be ready sometime in June.

If the Yankees do want Mitchell to make a spot start at some point, they'll need to clear room on the 25-man roster. They had optioned Gregorio Petit to make room for Whitley, but they were able to recall him because of Tanaka's injury. Without Petit, the Yankees didn't really have a backup infielder. The Yankees had optioned Chasen Shreve earlier in the year when they needed to make room for someone, but he's pitched so well that it's getting harder to justify sending him down.

Should the Yankees stick with the rotation the way it is? Should they call up Mitchell to make a spot start and give the rotation a rest?