Nigtengale also reported Sweeney will get $1.5 million in 2014 and 2015 with a $2.5 million option or $500,000 buyout.
Sweeney, 28, hit .266 with six home runs and 19 RBIs in 70 games with the Cubs this season after being signed to a minor-league deal in April, three days after he was released by the Boston Red Sox.
The left-hander was placed on the 60-day disabled list in late June after crashing into the an outfield wall. He returned in September as a part-time outfielder for the Cubs.
Sweeney can play all three outfield position and is a valuable fourth outfielder or pinch hitter should he be pushed to the bench. He also looks to be one of three starting outfielders next season for the Cubs.
Sweeney has hit .278 (532-for-1911) with 20 home runs, 14 triples, 115 doubles, and 204 RBIs in 605 career games.