CHARLOTTE, North Carolina – A guarded Michael Phelps dives into the unknown on Friday when he makes his first competitive appearance since his record haul of eight gold medals at the 2008 Beijing Olympics.

New events and a new weariness will be on display at the Charlotte Ultraswim Grand Prix meeting as the American lays the foundation for the program he will use to chase more Olympic glory in London in 2012.

"I'm just going to hop into the water and see what happens," Phelps told reporters on the eve of the meeting. "I have no idea how I'll do.

"We've been training for about eight weeks, dropped a bunch of weight and we'll see where we stand right now and see what we have to do."

Following the longest layoff of his career, Phelps is likely to regain top form before he can properly polish up his image.

The 23-year-old was left badly tarnished when he was photographed inhaling from a pipe used for smoking marijuana.

Although Phelps has never tested positive for any drugs, he was hit with a three-month suspension from USA Swimming for his colossal error of judgment.

"I made a stupid mistake and it's something I will learn from," he said. "You're guard always has to be up.

"Wherever I go I am really aware of literally everything around me. I have started doing that more and more recently.

"I'm always looking to see who is around me, see who's doing what, no matter who they are, whether I know them or not," added Phelps.

Constant screening

"I'm just constantly screening the area and making sure if I'm comfortable. If I'm not, I'm not staying there."

Coach Bob Bowman approved of Phelps's new approach.

"I think a healthy skepticism is good for him," said Bowman.

Phelps will swim in five events this weekend, the 50-meter, 100 and 200 freestyle, 100 butterfly and 100 backstroke.

Only the 200 freestyle and 100 butterfly were included on his Beijing program while the 100 backstroke and 100 freestyle are expected to feature on his list for London.

Bowman would not confirm his proposed London program but said the events and times he expected his pupil to swim at the 2012 Games had already been set.

"I just want him to race hard (in Charlotte), get a feel for what fitness he has and what his strokes are like," said the coach.

"There is a whole list of aims for 2012 and just like always they are private. The times are already set out for the Olympics.

"We have to know where we are now before we know what the world championships could bring (from July 18-August 2)," added Bowman.

"We have plenty of time to get to where he wants to be for London but it's hard to know what he can do in Rome until we've seen him swim a couple of times."