That is according to former world No 4 Robin Soderling.

The Swede’s best result at a Grand Slam was runner-up at the French Open in 2009 and 2010 when he was beaten by Federer and Rafael Nadal respectively.

And he competed against Djokovic and Federer several times over a 14-year career on the ATP Tour.

But in an interview with website Tennismash, Soderling said he believes Djokovic’s peak level is higher than Federer’s when at their best.

Soderling said: “I always had tough matches against Roger.