The upcoming UFC card in Belfast, Northern Ireland has undergone a dramatic change.

Gunnar Nelson has suffered an injury in training, forcing him out the fight with Dong Hyun Kim on November 19. Rather than find a late notice replacement for Kim, the UFC has decided to install a brand new main event as Gegard Mousasi will face Uriah Hall in a middleweight showdown in Ireland.

Sources close to the contest confirmed the switch to FOX Sports on Friday following an initial report from MMAFighting.com.

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UFC officials haven't announced the new matchup yet.

Mousasi and Hall will be meeting in a rematch from their first fight in September 2015. On that night, Hall pulled off the upset with a spinning back kick that led to a second round TKO over Mousasi.

Since that time, Mousasi has won three fights in a row but he's never forgotten about Hall or his desire to avenge the loss to him. Now he'll get his chance at the middleweights meet in the main event in Ireland.

Sources told FOX Sports that Nelson didn't suffer a severe injury, but it was enough to force the Iceland native off the card in November. There's no timetable yet for his return.