Chavis, 23, emerged as another potent slugger for Boston after making his Major League debut on April 20. The Georgia native knocked seven homers, drove in 19 runs and slugged .457 in May, and he became the third Red Sox player with at least 10 dingers through his first 35 big league games, joining George Scott (1966) and Sam Horn ('87). Chavis currently leads all AL rookies with at least 75 plate appearances with a .358 on-base percentage, and he ranks second in homers (10), slugging (.500), runs (22) and RBIs (28).
Riley, 22, has been a force since debuting with Atlanta on May 15. The Mississippi native homered Saturday to join Rhys Hoskins (2017), Trevor Story (’16) and Carlos Delgado (1994) as the fourth player in Major League history to go deep at least eight times in his first 16 career games. Riley’s first 15 games in May included seven dingers, two doubles and 20 RBIs as he slashed .356/.397/.746. According to Statcast, Riley’s 23 hard-hit balls (those hit with 95-plus-mph exit velocities) led the Braves for all of May -- even though he didn’t debut until halfway through the month.