The Hornets are currently three points behind second-placed Hull City but have a superior goal difference to their rivals.
Peterborough, who are one point off safety, come into the match on an unbeaten run of eight games that has included four wins.
Watford manager Gianfranco Zola has confirmed that he has no fresh injury worries ahead of the fixture.
Watford: Almunia; Doyley, Briggs, Cassetti, Chalobah; Ekstrand, Anya, Abdi, Battocchio; Deeney, Vydra
Sports Mole says: 1-2