This time, it's L.A. Chargers running back Austin Ekeler telling TMZ Sports he's just not very confident the 2020 NFL season will happen because COVID is still running rampant.

In fact, Ekeler points out that efforts to contain the virus without a bubble environment are failing -- but he's willing to do everything he can to help make the 2020 season happen.

"I'm not confident in the entire system because it is so contagious," Ekeler said.

"There's a reason we're going through all these shutdowns and things like that. There's not been really any progress made as far as containing this thing."

Just to be clear, Ekeler isn't going after the NFL's handling of the pandemic -- he's just saying pointing out the country ain't exactly in the clear yet.

FYI, Ekeler is set to report to training camp Tuesday (today) -- just days after MLB confirmed a COVID outbreak with the Miami Marlins that some say could tank the entire MLB season.

As we previously reported, 11 Miami Marlins players and 2 coaches tested positive -- and multiple games have been canceled as a result while the league scrambles to figure out a plan.

Meanwhile, in the NFL, some players are already opting out of the 2020 season due to COVID concerns ... but Ekeler says he's not considering that particular option.

"The thing is, what I can be is just confident in myself and I know I'm going to try my best to isolate and not be around anybody," Ekeler says.

"I'm just taking it day by day and I'm not gonna say that [the 2020 season] can't happen, but I'm just saying that we need to protect ourselves first before we can continue moving forward."

"I think that's what this period is right now, it's like, in my eyes, a trial period."

"I felt like, somewhat like a lab rat to see if this will work or not."

Despite not being able to have meet and greets with fans during the pandemic, Ekeler says he's using his Twitch channel to build a community with people around the world ... streaming anything from workouts to video games to giveaways to interact with his followers.

"I'm just trying to reach as many people as I can. These are all things I'm interested in as well."

Ekeler says he's started his own company, the Gridiron Gaming Group, to help fellow athletes build their brands in a similar way and make money in the process.