As the scheduled start of NFL training camps gets closer, the NFL Players Association has instructed player agents to talk to all of their clients about risk factors that could make them more susceptible to severe illness as a result of the coronavirus.

In a letter sent to agents Monday, which was obtained by ESPN, the NFLPA wrote, "The NFLPA is directing you to provide each of your clients with important risk factor information provided by the Centers for Disease Control that appears below, and by mid-July, you must engage each of your clients in a conversation about the vital importance of carefully reviewing this information with their personal physician. They should ask their personal doctors any and all questions they have regarding these risk factors in light of their personal medical history and their job as an NFL player. They should also discuss any risk factors with their team doctor."

The letter provides a link to the CDC page that discusses "people of any age with underlying medical conditions" and also spells out what the conditions are that put an individual at increased risk for severe illness from COVID-19.

They include, per the letter:

1. Chronic kidney disease

2. COPD (chronic obstructive pulmonary disease)

3. Immunocompromised state (weakened immune system) from solid organ transplant

4. BMI of 30 or higher: Obesity

5. Serious heart conditions, such as heart failure, coronary artery disease, or cardiomyopathies

6. Sickle cell disease

7. Type 2 diabetes mellitus

The letter includes a second list of conditions that the CDC has determined "might" put someone at increased risk of severe illness from COVID-19, including asthma, hypertension or high blood pressure, other immune deficiencies, liver disease, pulmonary fibrosis and Type 1 diabetes, among others.

"We want each player to be fully informed about his personal medical situation as he makes decisions about returning to play in the league and throughout the course of the season," the letter reads. "Proactive engagement in this manner will help players achieve that goal."

Per the new collective bargaining agreement between the players and the league, training camps may start no earlier than 47 days before a team's first regular-season game, which makes July 28 the reporting date for most teams. The NFL said last week that it is still planning to open camps and the regular season on time, although coronavirus health and safety protocols have yet to be finalized. The NFL and the NFLPA have been in regular discussions about those protocols as well as other matters, such as what would happen to players who decided it was too risky to play and what might happen with the 2021 salary cap as a result of lost revenue in 2020.