The NFL is stressing the importance of symptom reporting to prevent the spread of COVID-19 in a video featuring coaches Pete Carroll, Andy Reid, John Harbaugh and Ron Rivera.

“It is vital for all players, coaches and other personnel to understand and report symptoms immediately,†NFL Commissioner Roger Goodell said in a memo sent to teams on Tuesday and obtained by The Associated Press. “It is also essential for our medical staffs to continue their efforts to monitor everyone in the club environment.â€

Dr. Allen Sills, the league's chief medical officer, opens and closes the 2 1/2-minute video. Seattle's Carroll, Kansas City's Reid, Baltimore's Harbaugh and Washington's Rivera appear to repeat a simple message: “If you feel something, say something.â€

“We encourage players and coaches who are feeling ill, no matter how mild the symptoms, it is best to err on the side of caution,†Reid says.

Sills reminds players if they have symptoms but test negative, they will not be held out of the team environment.

“Symptom reporting is more important than ever,†Sills told the AP. “Vaccinated people may have very different symptoms. Last year, for those who had COVID-19, they might have a high fever and chills and trouble breathing ... and with the vaccination they may have only nasal congestion or a mild sore throat or a headache or fatigue.

“It's challenging to educate people to speak up about symptoms and get tests. It has to happen through multiple forums as we did with vaccinations. Through our athletic trainers and physicians and coaching staffs, there is lots of communication going on.â€

More than 93% of players and almost all club personnel are vaccinated.

“When an individual fails to report their symptoms, they are much more likely to bring the virus to their colleague and loved ones,†Goodell said in the memo. “This increases the risk to people around them and puts teams at a disadvantage. We can do better.â€

Sills is confident the league won't have significant problems playing out the season.

“I am much more optimistic than I was last year simply because we have safe and effective vaccinations we're able to deploy and create safer environments,†he said. “There were so many things we didn't know entering last season. We are in a much better place than last year and we have these important tools to use in this battle.â€

AP Pro Football Writer Barry Wilner contributed to this report.