Carolina Panthers left tackle Russell Okung, who missed 10 games last year with a pulmonary embolism due to blood clots, is evaluating whether to retire over coronavirus concerns, a source told ESPN on Friday.

Okung, who seriously considered opting out at Thursday's deadline, is comfortable walking away from the game if he feels the football environment is not safe, the source said.

In March, the Panthers traded guard Trai Turner to the Los Angeles Chargers for Okung, who has one year left on a four-year, $53 million contract. The Panthers appear open to Okung playing multiple years.

Okung, 31, was a first-round pick in 2010. He has made two Pro Bowls and has earned nearly $100 million for his career.

If Okung did retire, the Panthers could pursue his $2.5 million in signing bonus proration, but the Chargers paid the $10 million bonus upon signing his deal in 2017, and he hasn't played a down for Carolina.

Okung's embolism was diagnosed in June 2019, which he deemed a "wake-up call' during the season. He made a full recovery.

He played his first six seasons with the Seattle Seahawks, one with the Denver Broncos and the past three with the Chargers. In his last two healthy seasons, 2017 and 2018, Okung posted an 81.0 Pro Football Focus grade, ranking seventh among left tackles.