Joe Nathan apologized on Thursday morning for making two obscene gestures toward frustrated Detroit Tigers fans after his outing on Wednesday.

Nathan, the team's closer, was booed when he walked the first two batters he faced in the ninth inning but did not allow a run in the 8-4 victory over the visiting Pittsburgh Pirates.

"Hearing it the whole inning just got the better of me and my frustration came out," said Nathan, who has a 5.11 ERA with six blown save opportunities. "It was bad on both parts. Frustration came out on both sides and I apologize to the fans and apologize to my kids and I will be better."

Nathan has 24 saves, 24 walks and five home runs allowed, not what he or the Tigers envisioned when the veteran signed a two-year, $20 million contract in the offseason.

The 39-year-old is part of a bullpen that ranks 28th of 30 teams in ERA (4.35) entering Thursday's game.