The most difficult part for 49ers linebacker Fred Warner was the uncertainty.
When he tested positive and went on the NFL’s reserve/COVID-19 list on Aug. 31, he was not sure if he would be cleared in time for the 49ers’ season opener against the Arizona Cardinals just 14 days later.
Then, there were the more serious concerns, such as the toll the virus might take on his body.
With our All Access Daily newsletter, stay in the game with the latest updates on your beloved Bay Area and California sports teams!

“It was actually really tough in the moment,” Warner said on this week's episode of "49ers Talk." “There are a lot of unknowns with the virus. There is a lot of stuff being talked about with long-term effects, not just the immediate effects of it.
“I was worried about whether I was going to have any effects on my heart or on my lungs. Those are things that ran through my mind. Obviously, I want to be as healthy as I can to play the sport I love for as long as I can. That was scary at first.”
Download and subscribe to the 49ers Talk Podcast
San Francisco 49ers
Find the latest San Francisco 49ers news, highlights, analysis and more with NBC Sports Bay Area and California.
Warner, speaking publicly for the first time about his experience, did not address his health scare during the season, he said, because did not want to become a distraction to the team.
The 24-year-old was the third of 23 players on the 49ers to go on the reserve/COVID-19 list during the 2020 season. Players were subject to the list if they tested positive or came into close contact with an individual who subsequently tested positive.
“I was trying to help anybody else I could who was going through a similar experience as we went through the season,” Warner said.
RELATED: Warner closely followed Kittle's contract issue last offseason
Warner said his first practice back with the club was difficult due to his lack of conditioning.
But he did not experience any issues with his health throughout the season. Warner did not miss a game in his first three NFL seasons and was named to the NFC Pro Bowl team and was a First-Team All-Pro selection.
“Not that I experienced a bunch of symptoms or that it was hard on me physically, it was just the thought of not being with my team right before the season and not knowing if I’d be ready to go for Week 1,” Warner said.
“I’d put in all this effort to get my body and my mind right for the season and ultimately had to have a setback.”