Bob Weir, Phil Lesh, Mickey Hart and Bill Kreutzmann are reuniting under the official group name this July (15) to perform a trio of shows with Phish star Trey Anastasio to celebrate their milestone at Chicago, Illinois' Soldier Field, where they last played with tragic frontman Jerry Garcia, a month before his death in August, 1995.

Now reports Weir and company are considering returning to the road later this year (15) to join forces with Mayer on his autumn trek, playing as his backing band.

The news emerges two months after Mayer, who is a big fan of The Grateful Dead, rocked out with Weir on classic hits Truckin' and Althea while he guest-hosted America's The Late Late Show in February (15).

Sources tell Billboard Mayer and the members of the Grateful Dead have already started rehearsing for the tour, which is expected to kick off in October (15).

Representatives for Mayer and the Grateful Dead have yet to comment on the speculation.