According to MMAInterviews.tv, Sonnen and Munoz will meet in a No. 1 contender bout to determine the next challenger to face UFC middleweight champion Silva.
The Brazilian is currently rehabilitating from a shoulder injury he suffered during his bout against Yushin Okami at UFC 134, and Sonnen has previously stated he would opt to compete in another matchup as opposed to waiting for the champion to make a full recovery.
Also rumored to be on the card is a welterweight bout between Jake Ellenberger and Diego Sanchez, as well as a potential bout between Melvin Guillard and Jim Miller.
The winner of Sonnen vs. Munoz is expected to challenge Silva when he is slated to make his return to the Octagon in June 2012.
UFC on FOX is scheduled for January 28, 2012, from the United Center in Chicago.