Two weeks after being sacked by world number two Andy Roddick, Brad Gilbert was unsure whether his former pupil had made the right decision.
After joining forces with Roddick in June 2003, Gilbert had coached the American to the US Open crown and the number one ranking in less than five months.
However, earlier this month, Roddick abruptly severed his ties with the coach who had guided him to nine titles in 18 months.
"We'll know in year or two from now when we see what Andy's results are whether he made the right decision," Gilbert said on Thursday.
"He still has improvements to make and I thought I could help him with those. Whether he makes those with someone else only time will tell."
Roddick, who has recently hired US Davis Cup assistant coach Dean Goldfine as his new coach, failed to give any reason for the axing.
Roddick said his decision was based on "what I think is best for my game at this time".
However, Gilbert failed to deny media reports that Roddick had fired him because he did not get along with the player's father.
"I was completely caught off guard. I couldn't see any signs that it [the sacking] was coming," said the flamboyant Gilbert.
"Andy was the boss and it was his decision to make.
"Tennis is not a team sport. The relationship is between the coach and player and that's the way it should be."
Gilbert, who also coached eight-times Grand Slam champion Andre Agassi for several years, felt Roddick's failure to win one of the four majors during the past season could have contributed towards the player's decision to look elsewhere for advice.
"Andy's a tremendous talent," Gilbert said.
"But [world number one Roger] Federer has really raised the bar very high and it's up to everyone else to catch up with him.
"Andy had a pretty good year but for players like [Pete] Sampras, Agassi, Federer and Roddick, a good year is winning one Grand Slam. A great year is winning two.
"We were a couple points away in the Wimbledon final and Federer came up with the goods. You have to give him his props but that loss hurt the most.
"If Andy had won Wimbledon, we'd be looking at his year differently.
"But I stand by my record with Andy. It was pretty good."