The 6-foot-9, 245-pound forward has not played this season. He was acquired from the Minnesota Timberwolves in June along with the draft rights to guard O.J. Mayo and guards Greg Buckner and Marko Jaric in exchange for the draft rights to forward Kevin Love, swingman Mike Miller, forward Brian Cardinal and center Jason Collins.
In his 13th season, Walker has averaged 17.5 points and 7.7 rebounds in 893 career games. He played for the Boston Celtics, Atlanta Hawks, Dallas Mavericks, Miami Heat and Minnesota.
Walker was an All-Star in 1998, 2002 and 2003. He ranks fourth among active players (10th all-time) in 3-point field goals made (1,386) and second (sixth all-time) in 3-point field goal attempts (4,264).
The 32-year-old Chicago native was selected sixth overall in the 1996 draft by the Celtics.
"Antoine Walker was a true professional during his time in Memphis," Grizzlies general manager Chris Wallace said. "We wish him all the best in his effort to find another team where he can receive more playing time."