The coach clarified that Beckham hasn't tested positive for COVID-19.
Cleveland plays the 4-0 Pittsburgh Steelers on Sunday.
Beckham appeared in all 16 games last season but was limited for much of the year by a core muscle injury. He underwent surgery to repair the problem in January.
Staying healthy continues to be an issue for the 27-year-old, who missed 16 games combined in 2017 and 2018 with the New York Giants because of a variety of issues. Last year was only his second 16-game season in six years in the NFL.
The 2019 season was also a disappointment on the field, whether it was due to injuries or a lack of chemistry with quarterback Baker Mayfield.
During his first season with Cleveland, Beckham finished with 74 catches for 1,035 yards and four touchdowns. Though it was his fifth 1,000-yard season, he posted the lowest catches-per-game and yards-per-game averages of his career.
He has been up and down in 2020 as well, totaling 21 receptions for 294 yards and three touchdowns.
The three-time Pro Bowler will hope his illness won't hold him back as he tries to improve his latest results.