Derby defender Claude Davis is due to see a specialist on Tuesday in an attempt to cure a persistent knee problem.
Davis was unavailable for the 1-1 draw with Birmingham at the weekend and is keen to find the cause of the problem as soon as possible to enable him to be involved in the Rams' relegation battle.
With Tottenham next up for Derby on Saturday, Paul Jewell is also set to be without Stephen Pearson for the foreseeable future and has seen his preparations disrupted further by international call-ups.
"Claude will see a specialist regarding his knee problem and Pearo has had a few problems with his groin and hamstrings," the Rams' boss told the club's official website.
"We've got 10 players away on international duty or get-togethers as well so it's not ideal preparation for us on the training pitch this week, but of course it's the same for Tottenham too.
"It's a nightmare time because you are waiting for Thursday afternoon or Friday morning and you hope all the international players return fit and well."
Despite currently finding themselves cast adrift at the foot of the Premier League, Jewell has revealed that the mood in the camp remains upbeat after two hard-fought points against Manchester City and Birmingham in their last two games.
"It's been positive in training and we would have liked in training to build on the two results we have just had, but unfortunately that can't happen," he said.
"I don't think we are playing great football at the moment, but that goes for all clubs in the lower reaches of the Premier League right now because they are all playing survival football.
Planning for future
"We had a bit of a blip against Preston (in the FA Cup) but other than that we have picked up a bit, it's a slight improvement but I also know it's going to be a long time before I get to where I want to be.
"The summer starts now regarding recruitment of players and players we are looking to move on. It's a long drawn-out process but hopefully by the start of next season we will be where we want to be.
"It takes time to turn around a losing mentality but by the start of next season you will see major improvement from top to bottom."