Stefan Edberg needed to make one call before he agreed to work with Roger Federer for 10 weeks this year.

He picked up the phone to his old coach, Tony Pickard.

"That was nice of him," Pickard told Herald Sport. "He told me all about it, said he had a call [from Federer], asked my opinion and we had a conversation about it. I hope it all works out well for him.

"I said he had to think about what he was going to bring to the party. I know he went off to see Roger and I told him one or two things which are between him and I - one or two questions he should ask - which he obviously did and he came away with some satisfactory answers."

Edberg, who retired from the sport in 1996 after winning six grand slams, returned to the Tour this week but the partnership will remain temporary. The Swede lives and works in his home country, combining tennis with the financial world and Pickard, who coached him throughout his career, said he believed Federer was probably the only player that would have convinced him to return.

"I think it fascinated him, to be perfectly honest with you," said Pickard. "I think it was something that fascinated him and it was going to be a bit of a challenge to see what he was going to bring to the party and if he could help him improve. It's difficult to improve someone who's been No.1 for such a long while but there's always something you can do."

Severin Luthi, the Switzerland Davis Cup coach who has worked with Federer for several years, remains a part of the team and Pickard said Edberg was: "not being hired as a coach".

"He's employing him for expertise and for what Stefan can bring to help him stay at the top of the game," he said. "Okay, Stefan was No.1 in the world and so was Federer but one of the most difficult things when you're No.1 is to accept that somebody you're not very close to can bring something that may appear to be criticism."

"I think Stefan has accepted to go with Roger for this period of time and I think principally it's because he likes the man, he gets on well with him and he feels he can bring something to the party and help. But I would be very surprised if Edberg pulled up roots from his private life and business life to go back on Tour."

Federer plays Blaz Kavcic of Slovenia in the second round tomorrow.