Ravens star cornerback Marlon Humphrey has tested positive for coronavirus, he announced on Monday.
"I got the Rona hopefully I'll be back healthy soon," Humphrey said in a tweet.
Starting in Week 6, the NFL and NFLPA implemented game-day PCR testing, however, the results of Sunday's tests don't return until Sunday evening or early Monday.
The 24-year-old cornerback played in 100% of Baltimore's defensive snaps on Sunday in their 28-24 loss to Pittsburgh.
He finished the game with four tackles.
The Steelers said in a statement Monday that all of their test results from Sunday's game have come back negative and that they will follow the NFL's intensive protocols and take precautionary measures.
Humphrey, a first-round pick in the 2017 NFL draft, made his first Pro Bowl last season and was named First-Team All-Pro.
He has forced four fumbles this season, which leads the NFL.
Humphrey marks the first known Ravens player to test positive for COVID-19 since the start of the regular season. On Oct. 17, Baltimore defensive tackle Brandon Williams was placed on the Reserve/COVID-19 list, which was created for a player who either tests positive for COVID-19 or who has been in close contact with an infected person or persons.