"I got the Rona hopefully I'll be back healthy soon," Humphrey tweeted.
The All-Pro corner was active for Sunday's game against the Pittsburgh Steelers. In a statement, the Ravens didn't name Humphrey but said a player who tested positive is self-quarantining. The team is going through the NFL-mandated protocols after a positive test.
The Steelers are also going into intensive protocols to ensure they have not suffered an outbreak amid Humphrey's diagnosis.
Jeff Zrebiec of The Athletic reported Humphrey was sent home from the team's practice facility last Wednesday for what were believed to be cold-like symptoms. His COVID-19 testing came back negative, and he was able to practice Thursday and Friday before playing Sunday.
A case like Humphrey's shows the complications of dealing with COVID-19 because of the disease's incubation period. Colds and the seasonal flu also see increases in colder months, so teams will have to navigate difficult situations where players are symptomatic with illnesses that may not be COVID-19.
In Humphrey's case, he appeared to have a common cold until his testing came back positive four days after he showed initial symptoms.
It was a near-impossible situation to police unless the NFL were to implement rules that prevented players who show symptoms of any illness from being present at team facilities for a finite period of time. That could lead to pushback among teams and players since colds and the seasonal flu aren't as contagious or deadly as COVID-19.