Well, if you're going to pick two random athletes who would show up at a Nickelback concert, it's tough to say we're surprised it would be these two.
Apparently, both Tiger Woods and Roger "The Rocket" Clemens were in attendance backstage at the concert. At one point, the lead singer of Nickelback told the audience that there were some famous people in the house, and that he wanted them to come out on stage and shoot off some air cannons. First, he tells the crowd that Clemens is there, they go wild and "The Rocket" walks out on stage. Then he tells the crowd that Tiger is there, and they go even wilder, though it appeared that a lot of them didn't believe he was there. Well, Tiger walks out on stage, and I guess he too helps fire off the air cannons.
So there's an image: Tiger Woods and Roger Clemens shooting off air cannons at a Nickelback concert. And wait: Nickelback still tours? How depressing.
Tiger And Rocket, Nickelback Buddies [The Sports Oasis]