Travis d'Arnaud
Jose Trevino is set to be the starting catcher for the Yankees this year, but he's still a question-mark and the team could use a veteran to compete with him.
d'Arnaud is a 10-year veteran and represented the Altanta Braves at the All-Star Game last season. Although the Yankees shouldn't expect him to play every night, d'Arnaud could be a welcome addition to the organization because he'd elevate the catching position in the Bronx (and also help out big time at DH from time to time).
You're not expecting him to play every night, but it would be a good fit for the team down the stretch. You can use the first half of the season to evaluate the Trevino-Kyle Higashioka combo and then decide if this position group is in more dire need of an upgrade than elsewhere on the roster.
Since the Yankees don't know what to expect from Trevino (his lone productive offensive season was last year) and with Higgy's offensive game seemingly on the downswing, the worst-case scenario here could force the Yankees' hand.