Tony Gwynn having mouth surgery

SAN DIEGO -- Tony Gwynn, the Hall of Fame outfielder who 18 months ago blamed smokeless tobacco for a malignant growth inside his right cheek, was in his 13th hour of surgery Tuesday evening to remove a new cancerous tumor in the same spot.

According to Gwynn's wife, Alicia, doctors do not believe the cancer has spread outside of Gwynn's salivary gland. But she expects to know more after Tuesday's intricate surgery, in which she said five doctors would likely perform a nerve graft to preserve Gwynn's facial functions. The operation began at approximately 9:15 a.m. PT, and, as of 11 p.m. PT, the 51-year-old Gwynn was still in the operating room.

Tony told them to take [the malignant tumor] all out,'' Alicia Gwynn said Tuesday morning. "They said they may need to remove the facial nerve -- they might have to go a lot deeper. But he just told them to take it out. And if they do remove the facial nerve, they'll replace it with a nerve from his shoulder or his leg.

"Hopefully, his face will work fine; hopefully he'll be able to blink his eye. They said they will make his face as normal as they can -- and that it might be better than it was."

During the operation, which is being performed at the Moores Cancer Center at the University of California San Diego, doctors will conduct further biopsies of Gywnn's parotid gland, Alicia Gwynn said. She said if the cancer is localized, Gwynn should be able to return as San Diego State's baseball coach in about a month.

"Tony's very nervous,'' she said. "But once he's back on the field, he'll be fine.''

Tony Gwynn said he dipped smokeless tobacco inside his right cheek during his entire 20-year career with the San Diego Padres, and for another decade following that.

"I'm addicted," he has previously said of the habit.

Twice during his career, doctors found benign growths on the right side of his mouth, but Gwynn still kept dipping. Then, in August of 2010, a biopsy showed a malignant growth inside his mouth, and on Aug. 31, 2010, Gwynn had surgery to have most of it removed.

During that operation, doctors had peeled back the right side of his face and discovered that the malignant tumor was wrapped around one of his nerves.

That particular nerve controls the right side of his face, from his forehead to his eye to his mouth to his cheek. If doctors had removed the tumor entirely, the nerve would have been irreparably harmed and that side of his face would have been permanently paralyzed. He would never have been able to close his eye or eat without drooling.

Instead, the surgeons salvaged the nerve by leaving remnants of the tumor, hoping chemotherapy and radiation would clear the rest of the growth.

At the time, Gwynn's oncologist at Scripps Memorial Hospital, Dr. Prabhakar Tripuraneni, claimed there was no known link between smokeless tobacco and cancer of the parotid, the largest of the salivary glands. But the doctor acknowledged there had not been sufficient studies done to prove it one way or another.

At the time, Gwynn said "Of course it caused it ... I always dipped on my right side."

Since the 2010 operation, Gwynn has not used smokeless tobacco, instead opting for a safer, doctor-approved synthetic dip that he said "tasted awful." But in January, the cancer returned.

"He was upset," Alicia Gwynn said. "That's why he wants them to take it all this time."

Tom Friend is a senior writer for ESPN.com.