Hall (8-4), who scored three brutal knockouts en route to the TUF 17 finals, including a memorable spinning hook kick KO of Adam Cella, ultimately dropped his first two official UFC contests via split decision, losing first to Kelvin Gastelum then to John Howard.
The losses derailed what had become a remarkably large groundswell of momentum for Hall coming out of the show, and prompted UFC President Dana White to comment that Hall didn't "have what it mentally takes to fight" in the UFC.
He'll now meet Santos (9-2), a Brazilian prospect riding high after a 53-second TKO upset over Ronny Markes at UFC Fight Night 39. Though the 30-year-old's first UFC win stood in stark contrast to his promotional debut, a 47-second submission loss to Cezar Ferreira.
UFC 175 is scheduled to take place July 5, 2014 at the Mandalay Bay Events Center in Las Vegas NV. A middleweight championship bout between Chris Weidman and Lyoto Machida headlines the event, which is also expected to feature a battle between light heavyweight contenders Daniel Cormier and Dan Henderson.
Enz lost a unanimous decision to Clint Hester in his UFC debut, while Guimaraes is 1-1 over two Octagon appearances, first edging Dan Stittgen via split decision then losing to Hyun-Gyu Lim via second-round TKO at UFC on FUEL TV 8.