The New York Post reported Collins, who spent last season as the Mets' minor league field coordinator, will take over from Jerry Manuel, who was fired along with General Manager Omar Minaya after the end of last season.
MLB.com also reported the move, saying the official announcement could come Sunday night.
Collins, 61, hasn't managed in the major leagues since 1999, when he was fired by the Angels. He compiled a 444-434 career record during his stints with Houston and the Angels.
Collins most recently coached China's World Baseball Classic team in 2009 and the Orix Buffaloes of the Pacific League in Japan.