This afternoon, Assistant GM John Ricco told reporters it's possible both Lucas May and Vinny Rottino could be put on the taxi squad in the event they need to replace Nickeas on the roster.
No matter what, the Mets are in a tough spot if they have to make a roster move. Rottino has had limited major league experience behind the plate and hasn't caught in the minors yet this season. May isn't a great defender and has struggled offensively as well.
If it comes to this, Rottino might be more ideal option because he's more versatile than May. He showed an ability to play multiple positions during Spring Training, and so he would provide Terry Collins a little more flexibility off the bench.