ATLANTA — Look for plenty of introductions when the Atlanta Braves report for spring training Friday. The team underwent a massive shake-up over the winter, trading away three of its top hitters — Justin Upton, Jason Heyward and Evan Gattis — and getting mostly prospects in return. The 25-man roster that breaks camp in early April will probably include less than 10 players who were with the Braves at the start of the 2014 season.