A colossal UFC heavyweight matchup has been announced recently as former heavyweight champion Junior dos Santos and Alistair Overeem are set to face each other in the UFC on FOX 17 co-main event on Dec. 19 at the Amway Center in Orland, Fla.

As noted by MMA Weekly, the two fighters have been scheduled to fight each other twice before. Both times, Overeem was forced out of the fight. Back in UFC 146, the Dutch kickboxing expert was meant to challenge dos Santos for the UFC heavyweight title, but failed an out-of-competition drug test that led to the Nevada State Athletic Commission refusing him a license. Dos Santos wound up facing Frank Mir instead.

The two were set to collide again at UFC 160 after dos Santos lost his title to Cain Velasquez, but Overeem had to pull out due to injury. Dos Santos had to settle for knocking out Mark Hunt instead.

As pointed out by the report, by the time dos Santos finally steps into the cage to face Overeem, it would be a year since he last fought. The Brazilian boxing expert last fought at UFC on FOX 13 last December, when he won a unanimous decision over Stipe Miocic.

Meanwhile, Overeem last stepped inside the Octagon last March, beating Roy Nelson in a unanimous decision. He has won consecutive fights and three of his last four.

"Game on. I don't choose opponents, but I'm not gonna lie - it will feel great to shut this guy up. USADA Let's work," dos Santos wrote in an Instagram post.

"This is going to be fireworks," Overeem wrote in his own post.

UFC on FOX 17 is headlined by the lightweight title fight between champion Rafael dos Anjos and Donald Cerrone. In the their previous fight in 2013, dos Anjos won a unanimous decision over "Cowboy."