Jimmy Connors believes that Roger Federer will have to work even harder at his all round tennis game, having turned 30 earlier this week.
The 16 times Grand Slam winner has recently slipped to third in the world rankings behind Novak Djokovic and Rafael Nadal and 58-year-old Connors has revealed that more practice is required if the Swiss is to regain the number one spot.
"The older you get, the tougher things get," said the five time US Open champion.
"It gets harder going out and working on things that need to be improved. He's played an awful lot of matches but he if he's going to continue at this level, he's got to spend the time working on the right things.
"I'm just saying it gets tougher as you get older and everybody thinks because you're older that you have to rein it in and save yourself.
"It was the other way around for me. I needed to work harder."
Federer is currently competing in the Rogers Cup, a title he has never taken.