LLajic will be big, just how big depends on his attitude and the United coaching staff, which luckily for him and us, happen to be some of the best coaching staff in the world, not to mention the best manager in world football.
It will take two, three season atleast, we'll make him, stronger, faster and I have no doubt he'll become a United starter. I see him pushing Anderson for the starting playmaker role, or out on the left or right maybe.
My team for 4 years from now:
Neuer
Rafael Evans Vidic Fabio
Obertan Fletcher Anderson Llajic
Rooney Macheda