All these states which opened up are now putting billions of dollars in sports revenue in jeopardy.
The Latest on the effects of the coronavirus outbreak on sports around the world:
Clemson said 28 athletes or staff members have tested positive for COVID-19 since returning to school June 8.
Clemson has administered 315 tests since the school was given the green light to resume on-campus athletic activity.
Clemson athletic spokesman Jeff Kallin said most of those who tested positive have been asymptomatic for coronavirus and none have required hospitalization. All those who tested positive have been isolated for a period of at least 10 days. Close known contacts with those affected have been asked to self-quarantine for at least 14 days.
The state of South Carolina set a high-water mark for coronavirus cases in a single day, identifying 1,081 on Friday.
The Tampa Bay Lightning temporarily closed their facilities Thursday after three players and at least two staff members tested positive for COVID-19.
In a release posted on the team's Twitter account, general manager Julien Brisebois announced the players are self-isolating and are asymptomatic other than a few experiencing low-grade fevers. Anyone who may have been in contact with the individuals has been notified.
The team did not identify the players; it brings the count up to 13 NHL players having tested positive since the season was paused on March 12.
The positive tests come some two weeks after players were allowed to return to their respective facilities to take part in voluntary on- and off-ice workouts. Players were allowed to skate in groups of up to six at a time.
The move to open facilities was the next step in the NHL's bid to resume its season with a proposed 24-team expanded playoff format, with games being played in two hub cities.
The NHL projects teams to open training camps on July 10.
Tennessee announced that a member of the men's basketball team, who was not identified, tested positive after several members of both the men's and women's basketball teams were tested. Players from both teams started returning to campus Monday. The Vols are coached by Rick Barnes, who will be 66 in July.
Tennessee's sports medicine staff put the player in isolation and started contact-tracing protocol with the Knox County Health Department. Tennessee sports information director Tom Satkowiak says school officials are encouraged to see that their procedures work.
Tennessee football coach Jeremy Pruitt said Thursday that none of his returning players had tested positive, though a graduate assistant did test positive and went into self-quarantine.