The veteran is 49 and will make the start April 7 in Houston, Tracy said, which would give him the opportunity to set the record for the oldest Major League pitcher to win a game.
Tracy placed Moyer second on the starting staff behind Jeremy Guthrie.
Moyer broke into the Majors with the Cubs in 1986 and won a World Series ring with Philadelphia in 2008. He last pitched in 2010 when he underwent Tommy John arm surgery.
Colorado will be the left-hander's eighth team. He has a career 267-204 record with a 4.24 ERA.
Exploding whale video goes viral on Internet
Texas principal bans speaking Spanish, stirs controversy