Brazilian grappling specialist Paulo Thiago (15-5 MMA, 5-5 UFC) has been forced out of a planned UFC Fight Night 27 contest with “The Ultimate Fighter 17″ winner Kelvin Gastelum (6-0 MMA, 1-0 UFC). Combate.com first reported the withdrawal, pinning the decision on a knee injury suffered this past week. UFC officials are now seeking a replacement opponent for Gastelum. Featuring a headlining contest between Carlos Condit and Martin Kampmann , UFC Fight Night 27 takes place at Aug. 28 at Indianapolis’ Bankers Life Fieldhouse. The evening’s main card airs on FOX Sports 1 following preliminary bouts that air on FOX Sports 2 and stream on Facebook. Picked last on “TUF 17,” Gastelum outwrestled and outworked four straight middleweight opponents to earn a spot in the tournament final at The Ultimate Fighter 17 Finale. There, he pulled off a major upset by outpointing show favorite Urijah Hall to win the reality show