Derby County are set to be without Joe Ledley for the FA Cup third round trip to Manchester United with the Wales midfielder continuing to suffer from a back problem.
The 30-year-old has not featured in the last two Championship games against Ipswich Town and Sheffield United and has been unable to take a full part in training this week.
Tom Lawrence and Bradley Johnson are also doubtful for the promotion contenders. A hip issue has been hindering former United youngster Lawrence after he missed the clash with the Blades while Johnson picked up a knock in the 1-1 draw but completed the full 90 minutes.
"Joe tried to do some work yesterday and was a little bit stiff with his back," Derby boss Gary Rowett said, according to the club's official website.
"We would say that Joe is probably a big doubt. Tom Lawrence was hopeful that he would be able to train over the next couple of days, but he is a doubt.
"There are one or two others too – Bradley Johnson was a bit sore from Monday – but Joe and Tom are the only real doubts for the game.
"Both missed Monday's [1 January] match with Sheffield United, so with that, I think we will travel with a similar squad once again."
The ex-Burton Albion boss added: "It would be silly not to freshen up one or two positions – I'm not saying we're in a position to change the whole squad – so we will make some subtle alterations. We have got a big squad, with lots of players who are desperate for opportunities."
Residing second in the Championship with only two points separating them from the play-off positions, Derby have designs on returning to the Premier League for the first time since being relegated from the top flight in 2008.
Rowett, a former Rams defender who made over a century of appearances for the club, came up against United seven times during his professional career and as he chases his first win over the 12-time winners he admits he is not in awe of Jose Mourinho or his illustrious charges.
I've got massive respect for the titles he has won but you do that with any of the top managers," he added. "But am I going to be in awe standing next to one of the top managers? Not really. I'm just looking forward to the challenge.
"When you've been at this club as a player and you've played against Man United we've been there. I wouldn't look back as Derby manager and think this is an unbelievable game that we should be facing week-in, week-out. It is a look forward to the future.
"Is it a daunting task to go away to one of the top teams in Europe? Of course it is. Is it a daunting task to play against some of those players? Yeah but for me as a player and manager you have to embraced those challenges."