Abdi sidelined again
Almen Abdi will miss out once more as Watford entertain Doncaster.
Abdi was absent for Saturday's 1-1 draw at home to Charlton with a foot injury and that ailment again rules him out against Rovers.
Fellow midfielder Iriney, meanwhile, is now battling to be fit for the clash having sustained a leg injury at the weekend, although defender Joel Ekstrand returns to contention after illness.
Long-term absentees Nyron Nosworthy (Achilles) and Tommie Hoban (ankle) remain sidelined for a Hornets side who have drawn three and lost one of their last four Sky Bet Championship matches.
Federico Macheda could make his debut for Doncaster after joining on loan to provide competition for Chris Brown, Theo Robinson and Billy Paynter.
Harry Forrester missed Saturday's goalless draw at Huddersfield due to a knock he sustained in training and Tuesday night's game in Hertfordshire might also come too soon for him to be considered.
Fellow midfielder Marc De Val Fernandez is running again following his torn medial ligament but it could be three weeks before the former Real Madrid trainee resumes full training.
Centre-half Jamie McCombe is making good progress in his recovery from a back fracture but is still a long way from a return.