OMAHA, Neb. — Katie Hoff and Natalie Coughlin usually dominate their events in the pool. But the indefatigable teenager and the highly decorated Olympian rarely swim against each other.

That changes tonight at the U.S. Olympic trials, when Hoff and Coughlin face off in the 200-meter individual medley final. Hoff clocked the fastest qualifying time, while Coughlin was third quickest — 1.78 seconds behind the 19-year-old from Baltimore.

Hoff recalled racing Coughlin at U.S. nationals a couple of times, but never on a stage as big as the trials.

"She's going to be a great racer and I'll look forward to the challenge," Hoff said.

Both of them already have secured spots on the U.S. team for Beijing, so their matchup is all about adding another individual event to their Olympic schedules.

"I'm not thinking of the 200 IM as me against Katie or me against anybody," said Coughlin, who won five medals at the 2004 Athens Games.

The IM features all four strokes — butterfly, backstroke, breaststroke and freestyle. Coughlin's coach persuaded her to swim the event only a week ago.

"I can take it out fast in the fly," Coughlin said. "My backstroke is good, but not spectacular in the IM by any means. My breaststroke, I try and hold it together as long as possible, and then I have a good freestyle.

"But Katie, her middle 100 is her real strength. She definitely brings it home in the freestyle, but she's really good at the back to breast transition."

Hoff is 2-for-2 in finals so far. Besides the 200 IM, she'll be heavily favored to notch her fourth individual spot in the 200 freestyle final tonight.

Coughlin set a world record in the 100 backstroke Tuesday night to punch her Olympic ticket.