The team didn't describe the nature of the problem in a statement released Saturday. Whitney told the Pittsburgh Tribune-Review his left foot is misaligned and that attempts to correct it with orthopedic inserts in his skates didn't work.
"I just couldn't live on one healthy foot anymore, let alone try to skate," Whitney told the newspaper for Saturday editions. "We've tried everything to avoid surgery because we knew it would mean missing a chunk of the season, but nothing worked."
Dr. Robert Anderson operated Friday in Charlotte, N.C. The newspaper described the surgery as an osteotomy, defined as a procedure to shorten, lengthen or realign a bone or bones.
"Ryan has been bothered by this condition in his foot for some time," general manager Ray Shero said in a statement. "He consulted with a number of specialists in an effort to correct the problem without surgery, but it was ultimately determined that surgery was the best path to take -- for his general well-being and for his career."
Whitney is entering the second year of a $24 million, six-year deal.
Whitney signed the contract after a breakthrough season in 2006-07 when he had 14 goals and 45 assists. His production dropped to 12 goals and 28 assists last season, and he added a goal and five assists in the playoffs when the Penguins advanced to the Stanley Cup finals.
Whitney said his teammates knew his foot was in bad shape last season, but he doesn't consider it an excuse for his performance.
"I need to perform better than I did and I know that is the expectation," Whitney told the newspaper. "But I've always thought skating was the biggest part of my game, and last season I couldn't skate like I can."
The Associated Press could not immediately reach Whitney or his agent for comment Saturday. A team spokeswoman said Whitney was flying from North Carolina to his hometown of Boston.