Both the Hornets and the Reds go into the lunchtime game in high spirits after excellent starts to the new Championship season, Watford's spirits heightened by a late fightback at Reading last weekend that preserved their unbeaten record.
Forest have won all three of their league games to date but Zola knows that fortunes have been improvng at the City Ground since Billy Davies returned to the club earlier this year and sparked an unlikely late surge for a play-off place.
He told Watford's official club website: “They are a very good side when they have the ball. They have good balance, and it will be tough to face them."