Boxer Paul Williams has been seriously injured in a motorcycle accident near Atlanta, the fighter’s promoter, Dan Goossen, said Monday.

The 30-year-old Williams, who was scheduled to fight Mexican star and super-welterweight world champion Saul “Canelo” Alvarez on Sept. 15 at MGM Grand in Las Vegas, has no feeling below his waist, said Goossen, who added the southpaw fighter is scheduled to undergo surgery Wednesday at an unidentified hospital.

Williams resides in Aiken, S.C.

Goossen said he was told by Williams’ manager, Al Haymon, and trainer, George Peterson, that Williams apparently swerved to avoid contact with a vehicle Sunday and lost control of his motorcycle.

“Riding a motorcycle can be treacherous,” Goossen said. “I’m told Paul is in good spirits considering what has happened.”

Asked if Goossen has been told Williams will never fight again, the promoter said, “Our thoughts aren’t there right now. He’s undergoing this procedure, and we’re hoping he can get back on his feet after that. That’s all we’re hoping for.”

Williams’ manager told an Augusta, Ga., television station, WRDW, that the boxer’s surgery Wednesday will aim to stabilize the healthy upper half of his spine by putting a protective wall around it.

The 6-foot-1 Williams (41-2, 27 knockouts) defined himself as an active punching southpaw who could fight anywhere between welterweight and middleweight.

He struggled to get a fight as one of the sport’s most avoided boxers after scoring a unanimous decision over Mexico’s Antonio Margarito in 2007 at Home Depot Center in Carson, then rallying from a surprising loss to Carlos Quintana to knock him out in the first round of their rematch.

Williams, who was a world welterweight and interim world super-welterweight champion, beat current middleweight champion Sergio Martinez by majority decision in 2009.

In their rematch, on Nov. 20, 2011, Martinez beat Williams by second-round knockout.

Williams returned to edge Erislandy Lara in a controversial majority decision in July 2011, then dominated Japan’s Nobuhiro Ishida in February.

Alvarez promoter Richard Schaefer said last week that he was thrilled to match his star fighter against the active, respected Williams in what was to be Alvarez’s first headlined pay-per-view show.

“This is a fight where you don’t know who’s going to win, but you know it’s going to end in a knockout,” Schaefer had said.

Williams gained the Alvarez fight over Texas’ James Kirkland.

lance.pugmire@latimes.com

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