Coventry's already depleted ranks are stretched further by the loss of Gary McSheffrey for the visit of the Hornets.
The influential winger was forced off nursing a hamstring injury in the 18th minute of Tuesday's cruel late 2-1 reverse at Crystal Palace.
He now faces a spell on the sidelines and becomes City's eighth player in the treatment room.
Midfielder David Bell (hamstring) was the latest casualty to join the ranks before the Selhurst Park clash, with Gary Deegan (thigh), Clive Platt (knock), Richard Wood (thigh) and Jordan Clarke (knee) already sidelined.
Striker Freddy Eastwood (hamstring) and defender Ben Turner (knee) were hoping to return to light training at the end of this week but neither will be match-ready for the weekend.
One piece of good news for manager Andy Thorn is the return of midfielder Carl Baker, who has served the three-match suspension he picked up on the opening day.
Chris Iwelumo is a doubt as Watford look for their first win of the season.
The striker has emerged with a hip injury from the club's 4-0 defeat to West Ham on Tuesday night - their second second successive home reverse - and is being monitored by medical staff at Vicarage Road.
Manager Sean Dyche has been forced to defend Iwelumo from some early-season criticism, with the Scot having failed to find the net in three starts for his new club.
And whether the targetman is declared fit or not, the Hornets boss does have options in Troy Deeney and Gavin Massey if he wishes to change things around in attack.
Otherwise, long-term absentee Stephen McGinn (knee) remains the only player on the sidelines for a clash against a troubled Coventry side who have lost all four of their opening games in all competitions.