Roger Federer admits Novak Djokovic has underwhelmed recently, but has put a reality check on the hysteria around the Serb's form.

Speaking in a press conference in German, Federer was restrained in his assessment and reluctant to criticise his rival.

"Compared to a year ago, he's in a relatively difficult situation," Federer said.

"But, at the same time, he's still in the world's top four, in the race for titles, and easily inside the top 10.

"But there is no doubt that he has been weak for a player of his abilities. I guess it is not so bad, but it really depends on how you view his situation.

"Clearly last year was very good for him, especially during the first half of 2016. So it's quite surprising that he hasn't pushed on since winning the French Open last year."

Djokovic made it to the quarter-final of the French Open, but fell to Austrian Dominic Thiem, who was put out of the semi-final by eventual champion Rafael Nadal.

The Spaniard dominated Stan Wawrinka in the final at Roland Garros, claiming a straight sets victory to ensure himself of 'La Decima', his 10th title in France.

Nadal further improved on his good recent form and looks to surpass Andy Murray and return to his position as world number one before too long.

Federer doesn't think it will be too long before Djokovic is back up at that sort of level again, though.

"He is too good a player for this to continue indefinitely.

"He will win Grand Slams in the future and fight for world number one, so I expect to see a strong Djokovic in the future."

With the grass season about to begin and Wimbledon seedings to be announced in the coming weeks, Djokovic will be hoping to put a bad 12 months behind him.