Dec 28 (Reuters) - The National Football League and its players" union on Tuesday said players and staff who test positive for COVID-19 can return after five days instead of 10, provided their symptoms disappear or greatly improve, the league said in a memo seen by Reuters. The individual would need to go at least 24 hours without a fever, see other symptoms like a cough improve, and be cleared by a team physician after consultation with the NFL, according to the memo. The new guidance applies to all players whether they are vaccinated against the virus or not, although fully vaccinated players can "test out" sooner than five days by returning two negative tests after their initial positive. The memo said the changes to the policy came in light of revised Centers for Disease Control guidance released on Monday, which altered its recommended isolation time for asymptomatic cases to five days from the previous guidance of 10 days. read more Like almost all other sports leagues, the NFL has had a surge in positive cases amid the spread of the highly-contagious Omicron variant of COVID-19, with approximately 515 players having tested positive since Dec. 13, according to ESPN.