The Browns also placed S Karl Joseph on the active/PUP list with a foot injury and waived RB Brian Herrien.
The COVID-19 list was created this summer for a player who either tests positive for or who has been quarantined after having been in close contact with an infected person or persons.
Players will remain on the list until they are medically cleared to return.
Gilbert, 27, is a former sixth-round pick of the Rams. However, he was waived at the start of the 2014 season and later signed to the Rams’ practice squad.
Gilbert had brief stints with the Patriots, Lions and Raiders before signing on to the Panthers practice squad in 2017. He was on and off of the unit throughout 2018.
From there, Gilbert signed on with the Orlando Apollos of the AAF before joining the Browns in April.
In 2019, Gilbert threw for 2,152 yards while completing 60.6 percent of his passes to go along with 13 touchdowns and three interceptions. He also rushed for 79 yards and a touchdown.
Gillan, 23, signed with the Browns as an undrafted free agent out of Arkansas Pine-Bluff in 2019. He won the competition for Cleveland’s starting punter job.
In 2019, Gillan appeared in all 16 games for the Browns and punted 63 times with a 46.2 average, five touchbacks, 28 kicks placed inside the 20 and a long punt of 71 yards.
Joseph, 26, is a former first-round pick of the Raiders back in 2016. He finished his four-year, $11.88 million contract and was testing the open market as an unrestricted free agent for the first time in his career when he signed a one-year contract with the Browns this past April.
In 2019, Joseph appeared in nine games and recorded 49 total tackles, four tackles for loss, one fumble recovery, and three pass defenses.