Novak Djokovic has startled some fans on social media by posting photos showing he has grown a beard prior to his run on the North American tour.

23-time Grand Slam champion Djokovic has taken a well-earned break recently, prior to beginning his preparation for the US Open. The world No. 2 faced disappointment in the final of Wimbledon a few weeks ago when he failed to add to his seven victories at the tournament, which would have seen him equal Roger Federer's eight-win record.

Instead, he finished as runner-up to 20-year-old Carlos Alcaraz, who took the title after a five-set thriller. Djokovic now plans to compete at the Cincinnati Masters ahead of the Grand Slam at Flushing Meadows.

Even though he is currently away from the court, Djokovic has stirred up some debate among his fans about his new style choice. In photos posted on Instagram by @etnokatundurmitor, the 36-year-old was seen enjoying nature while sporting a beard.

This 'beard mode' has received mixed reactions on social media, with some approving of the new look:

"A break from shaving, huh? My husband says it's a nuisance," one user commented, while another compared the Serb to famous footballer Lionel Messi,

"He is more handsome with a beard, he looks like Messi in his 'beard mode'. It would be good if he kept it for good and never shaved it."

However, not everyone liked the new look:

"I hope he will get rid of it. I miss that boyish and clean face," one commenter wrote.

It remains to be seen if Djokovic will keep the beard when he goes to the US, but once he's playing tennis again it is likely that people will be more focused on that than his appearance.