Pulls 'DWTS' 2 Step ...
Dancing WHILE Touring
Multiple "DWTS" sources confirm the "Not Over You" singer has signed on for the new season -- the full cast will be announced on Tuesday morning.
Degraw's taking on a major work load -- the show premieres on March 19th ... but his tour continues through mid April.
We're told Gavin's dancing pro will most likely join him on tour so they can keep practicing -- but none of his tour dates conflict with 'DWTS' airdates.
As TMZ first reported ... Jack Wagner, Sherri Shepherd, and Melissa Gilbert will also compete for the mirrored ball.