Source: Michael Phelps to enter seven events at U.S. Olympic swimming trials

Michael Phelps is entered in a whopping seven events for next week's U.S. Olympic Swim Trials in Omaha, Neb., Yahoo! Sports has learned, conceivably laying the groundwork for an unprecedented 10 Olympic medals.

A source told Yahoo! Sports Tuesday morning that Phelps is entered in the 200- and 400-meter individual medleys, the 100 and 200 butterflys, the 100 and 200 freestyles and the 200 backstroke. If Phelps swims all those events at trials, makes the U.S. team and is part of all three American Olympic relays, he would have a chance to win 10 medals in London.

However, scratching out of one or more events at trials would not be surprising.

This figures to be a much tougher trials for Phelps than in 2008, when he was the singular dominant figure. This time around he has strong competition.

Phelps' seeding for the seven events is as follows: third in the 400 IM, behind Lochte and Tyler Clary; second in the 200 freestyle, behind Lochte; first in the 200 butterfly; second in the 100 freestyle behind Nathan Adrian; third in the 200 backstroke behind Lochte and Clary; second in the 200 IM behind Lochte; first in the 100 butterfly.

Phelps has not fully pushed himself to swim his best times yet this year. He will have to in Omaha to ensure he makes the U.S. team in all the events he swims.

Lochte is entered in nine events, but realistically does not have a chance at qualifying in more than seven. He is seeded first in the 200 and 400 IM, 200 freestyle and 200 back. He's fourth in the 100 back, fifth in the 100 fly and sixth in the 100 free. His long-shot events are the 100 breaststroke (26th) and 400 free (30th). Those are likely scratches.

Phelps made Olympic history four years ago by winning a record eight gold medals in Beijing. Although he was committed to competing again in 2012, most observers initially thought he would be undertaking a much less ambitious program at age 27.

But it appears Phelps is going to go as hard at the London Games as he did in 2008 – if not harder.

[Related: Pat Forde: Mark Spitz's seven-gold performance in 1972: part coronation, part redemption]

Of course, Phelps can still withdraw from some of those events if the program is too strenuous or the competition stacks up in a way that would be prohibitive for him to make the U.S. team. Only the top two swimmers in each individual event make the Olympic team.

One event Phelps had been adamant about not swimming after 2008 was the 400 IM, the most grueling event in swimming. But Phelps has begun rounding back into form in that event and has competed in it during some Grand Prix events leading up to the trials.

The new events from Phelps' 2008 Beijing program are the 100 freestyle and 200 backstroke. At the '08 trials, Phelps entered nine events and ended up swimming six at the Olympics.

Phelps is expected to duel with fellow American Ryan Lochte in several of his events, most notably the IMs. Both made the medals podium in both events in Beijing. Their competition should be one of the highlights of the meet in Omaha, which starts next Monday.

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