Danny Castillo has lost three of his last four fights. | Dave Mandel/Sherdog.com
Two bouts have been added to the UFC on Fox 16 bill.
Rustam Khabilov will square off with Danny Castillo in a lightweight bout, while Ramsey Nijem will lock horns with Erik Koch in another 155-pound pairing at the July 25 event in Chicago. A UFC official confirmed the matchups following an initial report from Fox Sports.
UFC on Fox 16 takes place at the United Center and is headlined by a bantamweight title rematch between T.