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 told Reuters in a telephone interview on Thursday.