Tennis player Boris “Boom Boom” Becker of Germany is the latest professional athlete to turn professional poker player. Becker, 40, who was known for his booming serve and who was once ranked the No. 1 male tennis pro in the world, told a German newspaper this week that he recently started playing poker seriously.

“I have already been playing intensively since last year,” said Becker, who won the men’s singles tennis title at Wimbledon three times and formally retired in 1999.

“What fascinates me about poker is the psychology,” he said. “What is my opponent thinking of me and what do I think of him?”

Becker told the newspaper he learned to play poker while on the pro tennis circuit, especially at Wimbledon in England during the many rain breaks.

He also said he looks forward to playing other former top tennis pros in poker.

“I would like to know how people like Andre Agassi, Pete Sampras, John McEnroe, Stefan Edberg, Ivan Lendl or even Jimmy Connors would manage to keep their cool at poker,” Becker said.

Becker said he plans to take part in a big poker tournament in Monaco in April, which is scheduled to bring together 800 professional players at the famed casino in Monte Carlo.

On the flacking front, Becker recently signed a deal with an online poker room to shill for the room.

That’s no surprise, as Becker has long been known as one of the top sell-anything-for-a-buck pro athlete endorsers.

During tennis matches, he often wore a wristwatch while he played, because he was getting big endorsement bucks from the watch manufacturer.

(E-mail Tom Somach at tomsomach@yahoo.com.)