Matt Brown injured, out of UFC Fight Night headliner against Kelvin Gastelum

UFC welterweight contender Matt Brown suffered an ankle injury during a training session and has been forced out of his upcoming welterweight bout with Kelvin Gastelum, which was set to headline UFC Fight Night (doubling as the TUF Latin America 2 Finale) later this month.

FOX Sports' Damon Martin reported the news on Monday night.

Brown (20-13) recently got back into the winning column with a first-round submission over the surging Tim Means this past July at UFC 189. Prior to that, he dropped consecutive losses to current champion Robbie Lawler and former 170-pound titleholder Johny Hendricks. Outside of the cage, he recently made the move to Elevation Fight Team in Colorado, where he now trains with the likes of bantamweight titleholder T.J. Dillashaw and fellow 170-pounder Neil Magny.

Gastelum (11-1) has looked fantastic since winning The Ultimate Fighter 17 with a split decision over current middleweight contender Uriah Hall. His only Octagon blemish so far has been a close loss to Tyron Woodley earlier this year at UFC 183, but he rebounded in June with a dominant stoppage over Nate Marquardt at middleweight. After missing weight badly prior to the Woodley bout, the promotion forced Gastelum back up to 185-pounds, but since then has been allowed to return to the welterweight division.

UFC officials have yet to announce a replacement for "The Immortal."

UFC Fight Night 78 takes place live from Arena Monterrey in Monterrey, Mexico on Nov. 21. Also on the card, top featherweight Ricardo Lamas welcomes Diego Sanchez to the 145-pound division, and it currently is the co-main event.