1:55 PM PT -- The Detroit Lions are clearing the air on Stafford's status ... saying he was placed on the COVID list due to a False-Positive result.
"Today we removed Matthew Stafford from the COVID-IR list and onto the Active Roster," the Lions said in a statement on Tuesday. "As a result of a False-Positive test result, he was forced due to NFL/NFLPA protocols to sit out until he received two negative tests."
"His testing sequence for the Pre-Entry period was: negative, negative, False-Positive. The next three tests were all negative."
"To be clear, Matthew does NOT have COVID-19 and never has had COVID-19 and the test in question was a False-Positive.
The team also says all of Stafford's family members have been tested ... and thankfully, all the results came back negative.
Another NFL superstar has contracted coronavirus ... Lions QB Matt Stafford tested positive for COVID over the weekend -- and has now hit Detroit's reserve list over it.
With his placement on the Lions' COVID list, the QB now has to pass several tests before he can rejoin the team.
Of course, the diagnosis is also a scary deal for Stafford's life off the football field ... his wife, Kelly, just gave birth to the couple's 4th child at the end of June.
Kelly has also undergone serious brain surgery in the last year and a half ... having a tumor removed in a 12-hour operation back in April 2019.
For her part, Kelly hasn't posted about the positive COVID test ... in fact, on Sunday, she celebrated her birthday by sharing an adorable picture of her, Matt and their kids with the caption, "Grateful for another year. This is 31. #familyovereverything #staffordstrong"