Adam Rubin of ESPN New York reports that Jason Bay (rib) will begin a minor league rehab assignment Saturday with High-A St. Lucie. Bay, who is currently working his way back from a non-displaced fractured rib, has been playing in extended spring training games this week. Barring any setbacks, the 33-year-old should be ready to rejoin the Mets as a DH next weekend against the Yankees.