Francisco Alvarez is set to begin a rehab assignment with Double-A Binghamton on Thursday, putting the slumping New York Mets one step closer to getting back their starting catcher. Alvarez was expected to miss six to eight weeks after having surgery on a torn ligament in his left thumb on April 23, four days after he slipped while rounding first base in a game against the Los Angeles Dodgers. President of baseball operations David Stearns said the Mets are encouraged by Alvarez's progress and eager to see how he handles catching.