Sunderland could be without their captain at the Liberty Stadium on Wednesday, as John O'Shea has a slight calf strain which he picked up in Saturday's 3-1 defeat to Arsenal in the FA Cup.
The Black Cats travel to South Wales for a midweek fixture with another relegation candidate, Swansea City, who are only four points above the drop.
A win would take Sunderland within a point of safety, making this a more than crucial game - one, therefore, that they will want their captain to be available for.
However, they won't know until tomorrow whether or not O'Shea can play, with the team to make a late decision on his fitness in order to give him as much time as possible to recover.
Allardyce confirms knock
Speaking to the Shields Gazette on Tuesday, manager Sam Allardyce confirmed that the Irishman was a doubt for the game.
"We'll wait until tomorrow morning [to make a decision]," the boss said, though he did add that, if O'Shea felt "right" today, he could "join in training."
However, whether or not that occurred is unknown, with us to now wait until the line-ups are revealed tomorrow night to see if the defender is capable of making the cut.
Replacements ready
With Younes Kaboul still sidelined with a hamstring problem, Sunderland have recruited a new central defender this month who could make his bow in O'Shea's absence - Jan Kirchhoff.
The German arrives from Bayern Munich and is eager to get going after an injury plagued few years.
Wes Brown is another option for Allardyce if he does not want to throw his new man in at the deep end though, especially in such a crucial game.
Brown has deputised for O'Shea once in recent weeks when the captain had another knock, whilst he has stepped in for Sebastian Coates too - who is the man set to make up the other half of whatever central defensive partnership is used at the Liberty.