Mets catcher Francisco Alvarez underwent surgery to repair a UCL tear in his left thumb, and he is expected to miss approximately eight weeks. The Mets initially placed Alvarez on the 10-day injured list but are likely to move him to the 60-day IL to open up a spot on the 40-man roster. Tomas Nido was selected to the major league roster to back up Omar Narvaez, who has struggled since signing a two-year free agent deal with the Mets.