The U.S. Olympic table tennis qualifiers are back in Cary this weekend, but this time they’ll have to compete against some Canadian rivals to claim a spot on the team headed to London for the 2012 Summer Games.

The final stage of the North America Olympic Trials for table tennis – beginning Friday at Cary’s Bond Park Community Center – pits the top four male and female qualifiers from the United States and Canada against each other for the remaining continental berths for the London Olympics.

One female Canadian, Zhang Mo, already has qualified after winning the Pan-American Games championship last fall, and under qualifying rules, her country needs only to win one more Olympic berth in Cary to bring a third Canadian to London for the team competition. The American women, on the other hand, must sweep this weekend’s tournament to earn the right to bring a third player to London.

U.S. women’s coach Doru Gheorghe said he expects his contenders – Ariel Hsing, 16, of San Jose, Calif.; Lily Zhang, 15, of Palo Alto, Calif.; Erica Wu, 15, of Arcadia, Calif., and Judy Hugh, 22, of Warren, N.J. – to have a slight advantage over their Canadian challengers.

“I hope the kids can take the pressure. You have to understand, we have a team [of teenagers],” he said. “There’s not a big difference between us and Canada. I’d say it’s 50-50, but I’m optimistic enough to say 51-49.”

The U.S. team will be without 1992 Olympic silver medalist Gao Jun, the top qualifier, who resigned her spot because of a knee injury she suffered in the World Team Championships in Germany. After Friday’s matches, the women will play a two-day, round-robin tournament, with the final Olympic spot determined on Sunday.

On the men’s side, the same “win two, bring a third” standard is in play, but neither Canada nor the U.S. has pre-qualified an individual for the Summer Games in London. That means there will be three mini-tournaments for the men, with an Olympic berth on the line each day. So it’s possible that two Americans will have to play each other for one of the Olympic slots in both the men’s and women’s competition.

Michael Landers, 17, of Old Westbury, N.Y., was the top player to come out of February’s American trials, also played in Cary. He is scheduled to be joined in this weekend’s field by Barney Reed, 33, of Milpitas, Calif.; Timothy Wang, 20, of Houston; and Judy Hugh’s brother, Adam Hugh, 24, also of Warren, N.J.

“They want it just as badly as we do. We’re just expecting to go to battle,” said Landers of the Canadians. “There are only three spots, and everybody wants to be in one of them.”

Gheorghe anticipates a tougher task for his men. However, the Canadian team took an unexpected hit this week when it learned that Eugene Wang, the 100th-ranked player in the world, was unable to receive a Canadian passport in time to qualify for this weekend’s trials.

“Right now, he’s the one entered, but it doesn’t look like he will fulfill the eligibility requirement” said Canadian coach Tony Kiesenhofer on Wednesday. “Someone dropped the ball in our government.”

But he remains optimistic, with or without Wang, who will be replaced by an alternate.

“We have a strong group,” Kiesenhofer said. “So anything less than two (singles) spots would be a disappointment.”