A text message left for Hunnicutt was not immediately returned.
Players were concerned for their health heading into the season, though none were injured as a result of the practices, according to one source.
Practice resumed on Thursday.
Grayson is ranked No. 1 in Class AAAAAAA, the state’s highest classification by the AJC. They are also No. 2 in the Southeast of the USA Today High School Sports Super 25 regional rankings.
The Rams finished 10-2 last season, Hunnicutt’s first with Grayson. The Rams won the 2016 AAAAAAA state title the year before in Jeff Herron’s lone season as coach.
The Rams are set to face Tucker at home on Aug. 25.
Score Atlanta/AJC reporter Seth Ellerbee contributed to this story.