Tennis:Novak Djokovic admits that Ivan Ljubicic knows his game well

Novak Djokovic admits he will find to strange to watch his friend Ivan Ljubicic working with Roger Federer during the 2016 season.

Federer announced in December that Croatian Davis Cup winner and former World No 3 Ljubicic would be working alongside his head coach Severin Luthi this year, after Stefan Edberg decided against spending a third year in the Swiss great's camp.

The hiring of Ljubicic was seen as a bid to break the current dominance of Djokovic, who won three Grand Slam titles last season, beating Federer in the final at Wimbledon and the US Open.

And Djokovic, who begins his season this week at the Qatar Open, admits that he may be a little disconcerted by the presence of a friend working for one of his main rivals.

Asked if he thought it would be strange to see Ljubicic in the Federer camp, Djokovic said: "Honestly, yes.

"He (Ljubicic) knows my game, he knows the game of all Roger's opponents, and I think that's one of the reasons why Roger has hired him to be with him on the team.

"Whether it's going to work or not, that's something to see for all of us, but I wish them all the best.

"Ivan is a great guy, very calm, very composed, and I am sure Roger knows why he hired him."

Federer, who will be in action this week in Brisbane, has denied that Ljubicic is on board merely to help him defeat Djokovic.

"What I like about him, he's very direct," said Federer. "He lets you know what he sees and thinks.

"We train very well together, he's got good insight.

"He's played against a bunch of players that I've played against and we played against each other over 15 times as well, so he knows my game very well."

Djokovic, meanwhile, could yet top his incredible 2015 campaign this year, when the players have a gold medal at the Rio Olympics to aim for, as well as the four Grand Slams.

Such was the quality of his play last year, it has even been speculated that Djokovic could become the first player since Rod Laver in 1969 to win all four of the Grand Slams in a calendar year.

"Grand Slams and Olympic Games are the priority of the season," said the Serbian.

"But it's a long season, so I can't really predict what's going to happen, or guarantee if I am going to win any of the Grand Slams or all four.

"Of course, I am going to try to win every tournament and every Grand Slam that I play, that's kind of the mindset that I have."