Lopez, 36, was 6-6 with a 4.42 ERA in 26 games with the Cubs in 2011. He helped fill the gaps created by injuries to Andrew Cashner and Randy Wells. In a four-game stretch last June 28-July 18, Lopez was 2-1 with a 1.85 ERA, posting three quality starts.
The right-hander signed with the Braves one year ago but did not make their roster out of Spring Training. He was traded to the Cubs in May, pitched in long relief and made 16 starts.
The Cubs also have signed catcher Jason Jaramillo, 29, to a Minor League deal with an invite to Mesa, Ariz. He has batted .235 in 366 big league plate appearances over the last three seasons with the Pirates. A second-round pick of the Phillies, he was bothered last season by an elbow injury. He'll compete with Welington Castillo and Steve Clevenger for the backup catcher's job on the Cubs.
The Cubs are expected to announce all the non-roster invitees next week.
Carrie Muskat is a reporter for MLB.com. She writes a blog, Muskat Ramblings, and you can follow her on Twitter@CarrieMuskat. This story was not subject to the approval of Major League Baseball or its clubs.