Tennis legend Andre Agassi believes that Novak Djokovic is capable of winning all four Grand Slam tournaments this year.

The Serbian star won the Australian Open in February after defeating Andy Murray over four sets in the final in Melbourne.

Agassi, who won eight Grand Slams during his career, says that the current world number one has the ability to go on and dominate 2015.

"I don't want to put pressure on him, but after watching Novak competing in Melbourne, I think there is a chance we might see a player winning all four Grand Slam tournaments in the same year," Agassi said on Tennis World.

"I believe Novak is playing above all others right now and he also has room for further improvements. If Rafael Nadal will not confirm his win at the French Open, I think we are going to see a domination this year from the Serb."

Djokovic has never won the French Open, but by doing so, he could become only the fifth man in the open era to complete a career Grand Slam - after Agassi, Nadal, Roger Federer and Rod Laver.