When he was the Tigers’ catcher, Brad Ausmus said he would develop some gray hair during the season from the stress of catching. Then, he said, that gray would transition back to black in the stress-free off-season. After Ausmus was named Tigers manager Sunday, president and general manager Dave Dombrowski said something that should keep Ausmus from getting some gray hairs. “We’re going to have a closer — we’re going to pursue somebody to pitch at the back end of the bullpen,” Dombrowski said. “Joaquin (Benoit) is in that group, but there are a lot of closers out there. It’s the one area where there are a lot of guys. “I think that is one area we need to address with him or someone else.” Benoit, the Tigers’ highly effective closer in the second half of this season, is a free agent. Other big-name free-agent closers include Tampa Bay’s Fernando Rodney, Texas’ Joe Nathan, Oakland’s Grant Balfour, Cleveland’s Chris Perez and the Dodgers’ Brian Wilson. After he missed more than a year due to elbow surgery, Wilson — the former Giants closer — excelled as a setup man with the Dodgers late this season as he came back from elbow surgery. Without such a bevy of closers last year, Dombrowski decided to give rookie Bruce Rondon a shot at closer and invested his free-agent pitching money to retain Anibal Sanchez with an $80-million deal. If Dombrowski is successful now, Ausmus will be spared the agony Jim Leyland encountered throughout his final spring training this year: wondering whether Rondon could close as a rookie and then, at the end, trying to go with closer-by-committee at the start of the season after Rondon got cut in the final week of spring training. Now it seems Rondon could be in line to become the eighth-inning setup man. Dombrowski also commented on the other front-line Tigers who have become free agents, displaced shortstop Jhonny Peralta and second baseman Omar Infante. He said it was “highly unlikely” that Peralta would be back because, as Dombrowski made clear when Jose Iglesias arrived, Iglesias is expected to be the shortstop for the next several years.