Brad Gilbert, former coach to Andre Agassi and Andy Murray, believes Australian Bernard Tomic got off lightly for his comments about being bored at Wimbledon and could have been suspended from the game.
Tomic, who said he could not find motivation during his first round defeat, was fined 11,600 pounds ($15,010.40) for "unsportsmanlike conduct" after also admitting he took a medical pause just to break up the momentum of the game.
On Thursday, the 24-year-old was dropped by his sponsor Head who disassociated themselves from his comments.
But American Gilbert, who has also coached Andy Roddick and Kei Nishikori and as a player reached the last eight at Wimbledon in 1990, said Tomic needed to question his own attitude.
"I'm 55 years old and I have been coming here since I was 21. This is the Cathedral of our sport and you should want to play here for free," he told Reuters in an interview.
"He needs to find in himself, why he said those things and why he acted that way.
"He got off light with the fine that he got. They could have taken his first round prize money off him and suspended him," he said.
Defenders of Tomic have said he has been attacked for being honest and that other players sometimes feel the same.
But Gilbert said that was no excuse.
"Whether he is honest or not, that is not how you act when you are a professional tennis player and he's been here at the quarter-finals.
"If you are bored, you need some soul searching," he said.
Gilbert's former protege, Agassi, who has admitted to "hating" tennis in the past, struck a different tone when asked about Tomic and life on the grind of the tour.
"It is not easy, for some people it is harder than others based on a variety of reasons. The fact that he is aware of how he is feeling, I think is a step in the right direction," he told Reuters Television in an interview.
"You have got to identify a problem before you can solve it. If he has identified that he is not liking the game then my suggestion would be go about finding your solution".