Nick Faldo is concerned 14-time major champion Tiger Woods will never play again.
Woods has been sidelined since the Wyndham Championship in August last year, undergoing multiple operations on his back.
Faldo, a six-time major winner, is worried about Woods' future, and feels the 40-year-old's career could be over.
"Physically, I don't think he is in good shape unfortunately. If you watched that promotion he did for his tournament recently when he walked onto the tee you'd see that," the Englishman told the Mirror and the Express.
"His back is basically locked up. He said he has had three surgeries on it and he's just not as flexible as you need to be for golf so I think unfortunately he's not looking good to even make a comeback as a golfer.
"We shall see."
In Woods' absence, Jason Day, Jordan Spieth and Rory McIlroy have taken centre stage, while Dustin Johnson won the U.S. Open.
Faldo is pleased to see a new group of stars emerge, ahead of The Open starting Thursday.
"It's now the big four," he said.
"Four years ago I was criticised for saying Tiger was slowing down and had probably won his last major and that all these majors were going to be divided up and that if these youngsters wanted some they had better get in there but that's what they done.
"Rory went off on a tear, then Jordan then Jason and now we have Dustin now as well. We have four guys playing really and a great chasing pack with Danny Willett and Justin Rose in it."