A rookie outfielder appears poised to crack Atlanta’s opening day roster, but it’s not top prospect Ronald Acuna. Dustin Peterson, who had a huge year for the Mississippi Braves in 2016, has had an outstanding spring for the Braves and is in the mix for playing time in left field. Peterson, 23, is batting .318 with two homers and six RBIs. The 6-foot-2, 210-pound right-handed hitter, acquired from San Diego in 2014, was a Southern League MVP candidate two years ago when he batted .282 with 12 homers, 88 RBIs and 38 doubles for an M-Braves team that played for the league title. Peterson played well in big league camp last year but suffered a broken hand that pretty much wrecked his 2017 season. “It’s a shame he got hurt because who knows what his story would be right now, the way he was swinging the bat last year,” Braves manager Brian Snitker told the Atlanta Journal-Constitution. Peterson batted .248 with one homer in 87 games at Triple-A Gwinnett, but indications are he’s got his power back this spring. P.S. Seven other M-Braves alums are currently projected by mlb.com to make the initial 25-man roster: Freddie Freeman, Ozzie Albies, Dansby Swanson, Johan Camargo, Julio Teheran, Arodys Vizcaino and A.J. Minter.