Catcher Alex Jackson was recalled from Triple-A Gwinnett before the team's game against the Miami Marlins.
McCann left Tuesday night's 5-1 win over the Marlins after the third inning due to soreness in the knee. Tests on Wednesday revealed the sprain.
The 23-year-old Jackson, who has hit .224 with 25 homers at Gwinnett, is making his second appearance of the season in Atlanta. He had no hits in 10 at-bats in three games from April 8-18 when McCann was out with a strained right hamstring.
More AP MLB: https://apnews.com/MLB and https://twitter.com/AP-Sports