"There's no doubt, 100 percent, that I can play in the National Football League today," Owens says.

The 47-year-old Hall of Famer tells us he's still in amazing shape -- claiming to have run a 4.4 40-yard dash just days ago -- and says if a team signs him, it won't be disappointed.

"I'm not washed up," Owens tells us ... adding, "Once you know how to ride a bike, you know, you don't forget how to ride that bike."

Of course, T.O. hasn't played a regular-season down in the league since the 2010 season, but he was effective that year ... piling up 983 yards and 9 TDs on 72 catches.

And, Owens says he really hasn't stopped training since ... despite being a free agent for more than a decade.

"I've been on the track, and, honestly, I just ran probably like a week ago," Owens tells us. "I was clocked at like a 4.4. Faster than I probably ever have in probably in a while."

In fact, Owens says he's actually drawn interest from at least one "individual" in the NFL this summer ... who the wideout says told him to stay in shape for the possibility of a signing this year.

"With that conversation that I had, they asked me to keep myself in shape -- anything can happen," Owens tells us. "And, so, that's what I'm doing."

In the meantime, while Owens waits for a possible call, the receiver is launching a new season of his "Getcha Popcorn Ready with T.O. and Hatch" show on Fubo Sports Network.