Sissoko’s compatriot Allan Saint-Maximin has started the season strongly at Newcastle, scoring in their 1-1 draw with Leeds United last Friday.
The Watford players are aware of the former France youth international’s talent, but also want to focus on their own game and play to their strengths.
“For me, he is a key player for them,” Sissoko added.
“You have to make sure to be close to him during the whole game and make sure he gets as little of the ball as he can because we know if we give him space, he has skills and he can bring danger at any time.
“He won’t be alone on the pitch, so you need to be careful of other players - if you only focus on one player another one can bring danger.
“But I think the main thing is for us to be focused on our own game, on trying to do what we want to do and play with our quality, and I think if we do that we won’t be far from winning the game.
“Let’s start on the front foot, be ready from the first minute and make sure that we are ready to win the game, because three points are going to be important for the rest of the season.
“That can give a massive boost to the squad for the future.”