McCann and his wife, Ashley, are expecting their first child. McCann had homers in four straight games before the All-Star break.
Manager Fredi Gonzalez says the team is waiting until Saturday to make a roster move to replace rookie shortstop Andrelton Simmons, who will miss at least a month with a broken right pinky. Simmons hurt his finger on a head-first slide Sunday in Philadelphia.
Gonzalez says the Braves could trade for a shortstop.
Veteran shortstop Jack Wilson, who had been the backup for Simmons, is starting in Friday night's game against the New York Mets. Martin Prado, starting in left field, would be the emergency shortstop.