The statue of former Watford manager Graham Taylor outside the club's ground is being boarded up ahead of the Hornets derby game against Luton Town.
Sunday's match, which kicks off at Vicarage Road at midday, is the first time the Championship sides have met in front of fans for 16 years.
Hertfordshire Police said the statue's protection was a "normal precaution".
The force added there would be a "significant police presence" in the town on matchday.
The last time the rivals played each other in front of a crowd was for a 1-1 draw in a Championship match at Vicarage Road in April 2006 - with Watford getting promoted via the play-offs the following month.