Regarding Dan, it was a minor problem with the hamstring that we hope to sort in 10 days or so.Pep Clotet.
The midfield playmaker limped off half an hour into Blues' win at Reading on Saturday with a hamstring issue.
However, Clotet says he doesn't expect the 22-year-old to be out for too long
"Regarding Dan, it was a minor problem with the hamstring that we hope to sort in 10 days or so," said Blues' Head Coach.
"We hope he will be back around Christmas."
On a more positive note, fellow midfielders Fran Villalba and Gary Gardner are both available for selection for the Rs fixture.
Villalba missed the Reading game at weekend with a slight hamstring issue, which he sustained during the second-half of Blues' last home game against Millwall.
And Gardner has not figured since mid-October after picking up a knee injury at Elland Road.
Gardner has been back in full training for a couple of weeks and played just over 70 minutes for Blues Under-23s at Nottingham Forest last Friday night.
"Gary and Fran are both available," said Clotet.
Elsewhere in the squad, Jake Clarke-Salter is out for two to three weeks are dislocating his shoulder at the weekend.
Marc Roberts is expected to be sidelined for a further month with his ankle injury and Maikel Kieftenbeld (knee) remains out until sometime in the new year.