Last weekend's 1-0 home defeat defeat to Bolton Wanderers left the Hornets in 10th place in the division, three points away from the playoff positions.
Yeovil, who have struggled all season, head into the match off the back of three straight defeats, but a surprise victory could put them in touching distance of 21st-placed Birmingham City.
With Watford facing tough away trips to Burnley and Leeds United in their next fixtures, many have been calling this a must-win match for Zola's men.
Possible starting lineups
Watford: Almunia; Cassetti, Angella, Doyley, Faraoni; Murray, Iriney, McGugan, Pudil; Deeney, Forestieri
Yeovil: Dunn; Ayling, Webster, Duffy, McAllister; Grant, Davis, Upson, Ralls, Edwards; Madden
Sports Mole says: 2-1