The Titans are making a big change in the middle of their offensive line – rookie Brian Schwenke is taking over at center. Schwenke the team’s fourth-round draft pick will start on Sunday against the 49ers. He replaces veteran Rob Turner who started the first six games of the season. “I think he’ll do a great job’’ coach Mike Munchak said of Schwenke. “We drafted him for a reason and we thought he was the best center in the draft. I think Rob did a good job but we think (Brian) has big-time upside and I think now is the time to give him a chance to prove it.” Schwenke was inactive for the first six weeks of the season after the Titans elected to start the season with Turner who signed a one-year $1.5 million deal after playing last season with the Rams. In recent weeks with the Titans struggling in the run game the team began thinking about making a move to Schwenke who impressed coaches during the offseason before suffering a hamstring injury in camp.