BOSTON -- There was powerful testimony Thursday in the medical malpractice trial involving former Patriots coach Charlie Weis.

NewsCenter 5's Amalia Barreda reported that Weis claims two doctors failed to act when he started experiencing complications from gastric bypass surgery. Weis' expert doctor faced some tough cross-examination.

San Diego surgeon Dr. Alan Wittgrove testified he has done 3,500 operations like the gastric bypass that former Patriots offensive coordinator Charlie Weis underwent in June 2002.

"All the symptoms that he had really showed that there was significant bleed, a hemorrhage and probably an associated leak with that," Wittgrove said.

Wittgrove told the jury obvious signs of a leak between Weis' newly stapled stomach and his small intestines appeared within hours after the surgery -- a leak that triggered heavy internal bleeding.

"It's important to operate as soon as you can," Wittgrove said.

Weis' doctors at Massachusetts General Hospital, Dr. Charles Ferguson and Dr. Richard Hodin, held off taking him back into surgery to repair it, opting to wait and see if the situation corrected itself.

"Waiting just prolongs the inevitable, and it allows the sepsis to take hold more in that particular individual," Wittgrove said.

Aside from having to battle a raging infection, Wittgrove said the wait also caused permanent neurological damage to Weis' legs and feet.

After Wittgrove testified -- he charges $7,500 a day for testimony -- the defense set out to paint Wittgrove as a very expensive hired gun.

Attorney Bill Dailey pressed Wittgrove to admit that in a previous case with similar circumstances, except the patient died, he testified the doctor gave appropriate care.

"I believe that is true in that case, yes sir," Wittgrove said.

It is expected that Patriots quarterback Tom Brady will testify Friday about how the operation affected his good friend and former coach.