Owls skipper Glenn Loovens is one booking away from a two-match suspension.
The commanding centre-back picked up his ninth yellow card of the season in Saturday’s heavy defeat at Fulham.
A player who collects 10 cautions between the opening day of the campaign and the second Sunday in April is automatically suspended.
Loovens, who served a one-match ban in September after reaching five yellow cards, has started 21 of Sheffield Wednesday’s 22 Championship fixtures.
At the start of December, Owls head coach Stuart Gray told The Star: “I don’t want players to go out there and be treading on eggshells. The last thing I want is for players to not be fully committed. If they get to the 10 yellow cards, then so be it.”
Wednesday are sweating over the fitness of Loovens ahead of their Boxing Day tussle with bottom-of-the-table Blackpool at Hillsborough. The Dutch defender sustained a hamstring problem against Fulham as the Owls slumped to a 4-0 loss.
Should Loovens be unavailable for selection, Claude Dielna is likely to partner Tom Lees at the heart of their rearguard, although Kamil Zayatte is edging closer to a first-team comeback.
Gray is demanding Wednesday get back to basics defensively after seeing his side concede five goals without reply in their last two outings. Fulham’s two first half strikes came from set pieces and Gray is keen for the Owls to cut out the individual mistakes which have plagued them in recent weeks.
He said: “We have got to stand up and be counted for and my players have got to take responsibility. They have got to give Keiren Westwood and the back four a breather by getting that first goal because teams will put you under pressure.
“We put pressure on ourselves.
“We have got to make sure we win against Blackpool.”