The decision was taken last night following a year that has seen former world number one Federer fail to win a Grand Slam and slip down the rankings.
"No, not really [it wasn't a surprise]," he told Sky Sports News. "If you look at his form this year, he has lost a lot of matches that he felt on paper that he should have won.
"He's tried to be more aggressive but he doesn't know where his balance is at the moment. He will probably take some time to himself, like he has done in the past.
"At the moment he is not knowing what he wants to do out there and with Paul the communication is obviously breaking down - these things happens."
Federer is still yet to qualify for the season-ending World Tour Finals in London.