With Rafael Nadal's future clouded by constant injury troubles, world number one Novak Djokovic stands firmly in the way of Federer and his 18th Grand Slam title.
Though 33-year-old Federer has beaten Djokovic recently, his last win against Serb in a Grand Slam came in 2012 Wimbledon final.
"It gets tougher from here but I still think Roger can win a Grand Slam," Ivanisevic told PTI today.
"He can also beat Novak in a major but if it goes down to the fifth set, Novak has a better chance because he is physically better. At the same time, Federer can wrap up the match in three or four sets. Federer is Federer.
