OMAHA, Nebraska (AFP) - Five-time Olympic medallist Natalie Coughlin tested the waters in the 200m individual medley Tuesday, notching the second-fastest time behind Katie Hoff in preliminaries at the US Olympic swimming trials.

The 200m medley seems tailor-made for Coughlin, a top sprinter in three of the four strokes.

She excelled in the event as a youngster, but had largely avoided it since failing to qualify at the 2000 Olympic trials.

"I had an emotional block with that event," said Coughlin, 25, who rebounded from her 2000 trials disappointment to win five medals at the Athens Games.

That included gold in the 100m backstroke, but no attempt at the individual medley. "I really thought I'd never do that event again," she said.

But in April, she swam the event in a meet in Stanford, barely qualifying for the final then swimming eight seconds faster. In June she broke the American record in the event.

"I knew a year or so ago that I would definitely swim the 100m back and 100m free (at trials)," Coughlin said Tuesday.

"I only considered the 200 IM a week or so ago, when too many people told me I should do it."

Hoff, the reigning world champion in the 200m medley, led the way into the semi-finals with a time of 2:12.02, with Coughlin clocking 2:12.21 as the top five swimmers went under 2:13.

Hoff has already secured her spot for two events in Beijing, the 400m individual medley and 400m free, and was also the top qualifier Tuesday for the 200m freestyle semi-finals.

In addition to the medley semi-final on Tuesday night Coughlin will try to cement her place in the 100m backstroke final, a day after losing and then regaining her world record in the heats in a duel with Hayley McGregory.

Michael Phelps will also do double duty on Tuesday night. With the final of the 200m freestyle on the schedule, Phelps took it relatively easy in qualifying third-quickest for the men's 200m fly semi-finals behind Davis Tarwater and Gil Stovall.

"Bob and I were talking about swimming a 1:55.7 or 1:55.8," said Phelps, who posted a 1:55.85. "It's about the same time I went in the morning of the worlds."

Phelps said the 40-minute gap between the free final and the fly semis should be plenty of time to recover.

"It's only the semi-finals of the 200 fly, and I should be able to come back and make it in," he said.

In other finals Tuesday, Beijing Olympic berths will be up for grabs in the men's 100m backstroke and the women's 100m breaststroke.