Swick disappeared off the MMA scene after losing in a technical knockout against Matt Brown in December 2012.
At the time it was his third loss in four fights for the welterweight. He has hinted at a comeback for sometime but surgery and health issues have held him back.
Last year Swick said that he would make a return and fight as a middleweight, having previously had a decent 5-1 record at that weight. The matchup with Garcia is unclear since he competes at 170 pounds.
Garcia is a full decade younger than Swick, but he has competed 10 more times since 2009.
The UFC 189 championship features reigning featherweight champion Jose Aldo battling division No. 1 contender Conor McGregor, while Robbie Lawler puts his welterweight title on the line against 170-pound wunderkind Rory MacDonald.