ROME — For those who thought Michael Phelps was just stopping by for a Roman holiday, no way.

This guy means business when he’s in the pool.

On to London!

As for he rest of the American swim team, well, there’s a little work to do if the country is going to maintain its position atop the world pecking order.

Even coming off his longest layoff and the embarrassment of being photographed inhaling from a marijuana pipe, Phelps turned in another remarkable performance over eight days at the Foro Italico. He completed it Sunday night by helping the U.S. set the 43rd world record of the fastest meet in history in the 400-meter medley relay.

OK, he didn’t win another eight golds. This time, he made do with five golds and a silver.

Still, Phelps showed plenty of fire, even when there’s really nothing left to prove.

“I never want to look back on my career and ask, ‘What if?'” he said.

No worries there. When Phelps is back in top condition, it’s hard to imagine anyone standing in the way of anything he puts his mind to.

That loss to Paul Biedermann? It just figures to fire up the world’s greatest swimmer.

Look what happened when Milorad Cavic tried to get in Phelps’ head.

“An incredible talent, an incredible background and probably the greatest mental toughness I’ve ever witnessed in an athlete,” raved Mark Schubert, general manager of USA Swimming, who was especially impressed with Phelps’ thrilling win over Cavic in a 100 butterfly showdown that featured plenty of smack talk beforehand.

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