Djordje is still young, we'll see what happens with him. As for Marko, I watched his match in Dubai against Golubev, I doubt he will have some great results in the future. However, Novak's brothers is likely to face with a lot of pressure because their brother was the best player in the world, it will not be easy for them.
''Laying awake in bed last night, I realized that in Federer's last 4 losses in Grand Slams, he has won a grand total of 1 set.'' - McEnroeisanartist