Freddie Freeman was the runner-up in the Rookie of the Year voting last year in the National League, and his numbers were stellar for a 21-year-old. While he was one of the (many) Braves who slumped in September last season, his expected improvement is one of the reasons that the team felt they didn't need to make a substantial move in the offseason.
But his 2012 start will have to wait. From Mark Bowman:
Freddie Freeman will likely spend the next two weeks resting a right knee injury that he suffered during Tuesday morning’s workout at ESPN’s Wide World of Sports complex.
Freeman mentions that he suffered a similar injury in the minors in 2010, and he came back within a week, but the Braves are obviously going to play it safe with their prized youngster in February and early March. There doesn't seem to be any doubt that he will be ready for the start of the season, though,