Deftones bassist Chi Cheng was forced to undergo emergency surgery on his foot yesterday in Sacramento, and has been ordered by doctors to drop off the band's current opening stint on Black Sabbath's Reunion Tour.

Cheng was with the Deftones when the Sabbath tour kicked-off on January 25 in Houston, but was immediately rushed to an area doctor after the show. On Tuesday, Cheng flew from Houston to Sacramento to have surgery done on the big toe of his left foot by specialists.

Representatives for the band say that Cheng originally had corrective surgery on the toe back in June, but apparently aggravated the injury a few weeks ago when the Deftones were headlining the Australian edition of the Warped tour.

The Deftones have tapped Quicksand's Sergio Vega to stand-in for Cheng for the rest of the group's dates with Black Sabbath, which is now scheduled to run until February 23.

Cheng will rest at home for the next month, but is expected to fully recuperate by the end

of the tour -- after which the Deftones plan to head into a studio and start work on their next album.