updated 9:16 p.m. ET June 11, 2009

SANTA CLARA, Calif. - Michael Phelps has descended from the mountains of Colorado still stinging from two recent losses in the pool.

The 14-time Olympic gold medalist feels he has something to prove, mostly to himself, and he hopes to avenge those defeats this weekend at the Santa Clara Invitational Grand Prix.

Last month, Phelps was beaten by a couple of world recordholders in the 100-meter freestyle and backstroke events at the Charlotte Grand Prix, his first meet since capturing a record eight gold medals at the Beijing Games. He also won two events — the 100 butterfly and 200 free — but that’s not what he remembers.

“I can’t stand to lose, no matter what stroke it is,” he said Thursday after practice at the outdoor pool where wind whipped up the water. “I can always turn a negative into a positive. If I’m disappointed, it’s going to motivate me.”

Phelps is back in serious training, having spent the last three weeks at high-altitude. He’s got structure again in his daily life, and that’s just the way coach Bob Bowman likes it.

“He’s now back training really well,” Bowman said. “We’re still in the experimental stage with his freestyle stroke, so you never know what you’re going to get.”

Phelps unveiled a new windmill-like motion in his freestyle stroke at Charlotte, mixing it with his normal bent-at-the-elbow technique to pick up speed.

“I’m swimming with an open mind,” he said.

The nine-month layoff that ended last month was the longest of Phelps’ career, though he had intended to come back earlier.

Slideshow Phelps' 2008 Olympics Take a look at how Michael Phelps became the most decorated gold medalist in Olympic history at the 2008 Beijing Games. NBCSports.com

Those plans were derailed after he was photographed using a marijuana pipe, a picture that wound up on the front page of a British tabloid, and he was handed a three-month suspension by USA Swimming.

His return in Charlotte attracted a gaggle of media, where he faced relentless scrutiny and questions about his life out of the pool. Things are downright laid-back at Santa Clara, a low-key meet that has attracted some of the world’s best swimmers over the last 42 years.

“I feel at home and more comfortable,” Phelps said. “I’d like to move forward and be able to look back at the training we’ve done this year and say we got something out of it.”

Phelps swims his first event, the 200 fly, on Friday. He’s the world recordholder with a mark he set in Beijing. That time is nearly 4 seconds faster than his closest challenger in the event.

Things will get more interesting on Saturday, when Phelps swims the 400 free. He comes in as the third-fastest qualifier in an event where Australian great Ian Thorpe still owns the world record.

“I want to be able to swim the 400 free the right way,” Phelps said. “I always take the first 200 out hard.”

He’ll cap off the weekend with two races on Sunday, taking on rival Ryan Lochte in the 100 free and 100 back. Those are the events Phelps lost in Charlotte.

Swimming the 100 back outdoors poses new challenges.

“You have nothing to look at, so it’s going to be hard to stay in a straight line,” Phelps said.

Slide show   Week in Sports Pictures Flying on the hardwood, racing on the rink, getting physical on the gridiron, and much more. more photos

Relegated to the scrap heap are the 200 free and 200 and 400 individual medleys — all events in which Phelps owns the world record and won in Beijing. He’s remaking himself as a sprinter in the four-year push to the 2012 London Games, his final Olympics before retirement.

Lochte, who won four medals in Beijing, is entered in eight events this weekend. Also planning a heavy workload is Katie Hoff, who now trains with Bowman after she failed to win a gold medal in Beijing. She’ll resume her rivalry with Australian Stephanie Rice in the 100 and 200 freestyles, in addition to being entered in five other events.

Rice is one of several Aussies at the meet, along with Olympic champion Leisel Jones.

Dagny Knutson, a 17-year-old from Minot, N.D., who trained with Phelps in Colorado, will be trying to position herself for big results at next month’s U.S. nationals, where the team for the world championships will be chosen.

Knutson won seven medals, including six gold, at the junior national championships in Guam in January. The budding star will test herself in five events this weekend, going against Hoff, Olympic champion Rice and Kirsty Coventry of Zimbabwe.

Also on NBCSports.com Howard: Look at what Agassi is now, not was PFT: Cowboys on rise in our power rankings NCAA FB: Ready for player exodus?  |    Top juniors   MLB blog: A look at the top 111 free agents Twitter: Follow us @nbc_sports

MORE FROM OLYMPIC SPORTS

Olympic Sports Section Front

Phelps finishes second in 200 IM at World Cup Jing Zhao sets new women's 100 medley record Americans Marshall, Hardy set swim world records Hardy beats own world record in 50 breaststroke Jeremy Bloom retires from moguls skiing Davis sets course record to win 1,500 Cohen bows out of Skate America with tendinitis Ohno fails to qualify for 1,500 final 10 storylines to look for at the Winter Games Video: Go in-depth with Vonn Olympic Sports Section Front   Add Olympic Sports headlines to your news reader: