The deal is believed to be for one year and slightly more than the veterans minimum.
ESPN.com's Marc Stein initially reported Tuesday that West would return to the Mavs.
The Mavs exhausted their salary-cap space with last week's signing of shooting guard O.J. Mayo and currently have 15 players under contract. West, celebrating his 29th birthday Thursday, is just one of seven players to return from last season's club that finished 36-30 and was swept out of the first round of the playoffs.