Troy Deeney is a doubt for Watford's home clash against Derby while Almen Abdi and Davide Faraoni definitely miss out.
Six-goal leading scorer Deeney is struggling with a calf injury and faces a late fitness test ahead of the encounter at Vicarage Road as the Hornets get back into action following the international break.
Abdi continues to sit out with the foot injury which has sidelined him since the end of August, while fellow midfielder Faraoni serves a one-match suspension having collected his fifth booking of the season in the 2-1 win at Huddersfield last time out.
Long-term absentees Nyron Nosworthy (Achilles) and Tommie Hoban (ankle) also remain unavailable although the former is closing in upon his return.
Will Hughes stands a good chance of being fit for Derby.
The highly-rated midfielder was forced to withdraw from the England Under-21 squad with a groin injury but after receiving treatment Hughes has trained this week and Steve McClaren is optimistic of having him available for his first away game since becoming the Rams' head coach.
Fellow teenager Mason Bennett could start up front after impressing McClaren from the bench against Leeds a fortnight ago and following that up with further good performances for the England Under-19 side.
Midfielders Paul Coutts (dislocated kneecap), Jeff Hendrick (ankle) and James Bailey (knee) and goalkeeper Adam Legzdins (ankle) remain out injured.