The Steelers were dealt a major blow on Friday when both Joe Schobert and Chris Wormley were placed on the Reserve/COVID-19 List.
The move puts the status of both in jeopardy for Steelers' game Monday night at Heinz Field against the Browns.
It leaves the Steelers (7-7-1) potentially missing two starters on their defensive front against the Browns (7-8), who are third in the NFL in rushing at just under 145 yards per game.
Schobert, acquired via trade from the Jaguars just before the start of the regular season, is second on the team with 108 tackles from his inside linebacker position.
Wormley had already been filling in for Stephon Tuitt, who has been out all season. Wormley missed last week's 36-10 loss to the Chiefs with a groin injury, but had returned to practice in full on Thursday.
With the NFL's new COVID-19 protocols put in place this week, both would have a slight chance of returning to play Monday if they can test negative twice within a 24-hour period between now and Monday.
In the past week, no fewer than eight players have landed on the Reserve/COVID-19 List but then been activated in three days or less afterward. But that also requires the player to be free of symptoms.
The Steelers have already been hit hard by COVID-19 at the inside linebacker position. Robert Spillane, Devin Bush and Marcus Allen have all been on or are currently on the COVID-19 list in the past month. Spillane is now active, while Allen was activated earlier this week. Bush was placed on the list Dec. 22 and is likely to be cleared to return to play before Monday's game.
With Bush and Allen out against the Chiefs, Spillane and Schobert played 66 and 60 defensive snaps, respectively, with Ulysees Gilbert playing nine in his first action on defense this season.
With Wormley out against the Chiefs, rookie Isaiahh Loudermilk played a season-high 35 defensive snaps. The Steelers did get nose tackle Montravious Adams, who had been on the COVID-19 List, back for that game, but were without Isaiah Buggs, who went on the list Dec. 23.