Athletes like LeBron James, Peyton Manning, and Derek Jeter might be superstars today. But once upon a time, they were young rookies just trying to get ahead in the world by doing their best on the court or field. Bleacher Report just took a look back at their rookie years by putting together a list of 20 sports superstars as rookies over here. Take a trip down memory lane to see what those 20 athletes looked like at the starts of their careers.

[via Bleacher Report]