The club has yet to confirm the deal, but Stewart tweeted: "Glad to be healthy and back with the Cubs. The support from the Cubs organization and the fans has been incredible. Thank you all so much."
A wrist injury limited the 27-year-old left-handed hitter to 55 games last season, his first with the Cubs after spending his first five years with the Rockies. He finally resumed light baseball activities this week and now gives the Cubs another option at a thin position, where his competition figures to include Josh Vitters.
Stewart put up a .201/.292/.335 batting line in 202 plate appearances last season, with five home runs and 17 RBIs. He started 49 games, all at third.
The Cubs acquired Stewart from Colorado last Dec. 8 in exchange for outfielder Tyler Colvin and infielder DJ LeMahieu. Stewart, who hit 25 home runs for the Rockies in 2009, batted .156 without a homer in his final season with the club. He sports a career line of .232/.319/.417 at the plate.
Andrew Simon is a contributor to MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.