Mazzarri and Conte had been fierce opponents within the Serie A, when in charge of Napoli and Juventus respectively.
The Italian pair's relationship grew to become frosty after Mazzarri apparently took exception to what he believed to be Conte imitating his 3-5-2 formation within the race for the Scudetto.
Mazzari and Conte will go head-to-head within the ultimate League on Saturday, however the former attempted to play down the rivalry.
"Friendship is a very primary suggestion," Mazzarri advised journalists.
"I respect Conte as a individual and a supervisor. I recognize him rather a lot but friendship is a lot, it's a further factor."
Mazzarri introduced: "Of course we will shake hands.
"We even shook palms on the assembly of the managers on the start of the season.
"there is no obstacle however again for me friendship could be very most important. I've only a few associates."
Watford welcome Chelsea to Vicarage avenue, having opened the season with a 1-1 draw at Southampton final week, whilst Conte's men claimed a late 2-1 win over West Ham.