The Rams are looking to secure a play-off spot but head coach Steve McClaren is set to be without midfielder Bryson and defender Whitbread against Millwall and Reading after both players limped off against Huddersfield on Saturday with respective thigh and hamstring problems.
The rest of the Derby squad has travelled to Spain for a training camp ahead of the trip to The Den at the weekend but Bryson and Whitbread have remained behind to receive treatment.
Whitbread has endured an injury-plagued season. The centre-back has only recently returned to action following six months out with back and hamstring problems.
Bryson has endured a stop-start campaign and thigh injuries can keep a player out for several weeks – as fellow central midfielder George Thorne has found.
Thorne missed six matches towards the end of February and a recurrence of the injury has kept him out of the last four games.
However, he has travelled to Spain along with Chris Martin and Jake Buxton who have been out recently with hamstring and back injuries.
Victory at relegation-threatened Millwall will guarantee Derby a play-off spot.