Bake the meatballs according to the package directions; set aside.
Slice each roll in half to make a top and bottom. Place to meatballs on the bottom half of each roll and add 1 Tbsp marinara. Top with 1 Tbsp mozzarella cheese. Cover with other half of the roll.
Insert a toothpick into each roll to hold meatballs in. Serve hot.