The Clippers reached a deal late Tuesday night with Jackson, the 13-year NBA veteran. Los Angeles' lengthy East Coast road trip continues Wednesday in Boston.
The Clippers have lost J.J. Redick, Matt Barnes and Reggie Bullock to injuries in recent weeks, forcing the Pacific Division leaders to search for depth.
The 35-year-old Jackson spent last season with San Antonio, averaging 6.2 points and 2.8 rebounds. The Clippers are the eighth NBA team for the veteran, who won a title in 2003 with the Spurs.
Redick will be out for several more weeks with a broken bone in his hand, while the Clippers hope for a quicker return by Barnes (torn retina) or Bullock (ankle sprain).
