The 40th meeting of the two sides takes place at Vicarage Road where Lewis McGugan made a summer move after 200+ appearances in a Nottingham Forest shirt.
The midfielder has started all of Watford's league games to date and netted in their 6-1 hammering of Bournemouth on his home league debut.
The Hornets staged a late fightback to claim a point at Reading last weekend and maintain their unbeaten start to the campaign.
“It pleased me that we didn’t give up," said manager Gianfranco Zola afterwards.
"That is the good thing with this team; you can score one or two goals against us but the game is not finished. I am delighted to see that."
Former Forest loanee Scott Wootton, meanwhile, has joined Leeds United on a three-and-a-half year deal from Manchester United.