Tunez missed Buriram's 1-0 win over Chiangrai United in the Thai Premier League on Friday as he had not returned from international duty after representing Venezuela in their friendlies against Jamaica and Peru.
However, with the international break over, Tunez has returned to help Buriram keep their unbeaten streak in the AFC Champions League intact.
"This game is very important for us," Gama told the official AFC website. "We will play in front of the fans and we need three points to guarantee that we will pass the first round. I believe that the hot weather will affect the performance of Gamba.
"We do not have any problems regarding injured players. Tunez’s symptoms from last match resulted from his travelling. He is surely ready for this game. We also have enough players for rotating during this game."