The big striker has been mainly used from the bench so far this season since his arrival from Sassuolo in the summer.
But Zaza was in the goals at the weekend as the Italian international scored in Juve's 3-0 win over Palermo.
It was his third goal from nine appearances this season and talk after the game suggested he could be set to leave the Turin giants in the winter window.
'The player isn't on the market'
The news will come as a blow to the Hammers - who are suffering something of an injury crisis - as well as the Hornets and Stoke City ahead of the January window.
“He’s scored three goals in nine incomplete matches, because he’s only started three,” Maifredi told TuttoJuve.com.
“There are many games in December and there will be more chances of playing. I think that at a team like Juve nobody, or almost nobody, can complain.
“Watford and Stoke City? Now we’re about to enter the January transfer market.
"We haven’t had any kind of contact yet from any club... the player isn’t on the market and there are still many games left to play.”
Zaza would be a major coup
Zaza would be a major coup for most Premier League sides and should he continue to be among the goals could even attract interest from more illustrious clubs.
The hard-working forward was also reportedly courted by the likes of Arsenal and Tottenham Hotspur late in the summer window, as reported by talian website Tuttomercatoweb at the time.
Given how open the Premier League is this season he would undoubtedly make a welcome addition but it looks for the moment at least to be a non-starter.