Silva has overseen just one defeat from his opening seven league fixtures as Watford boss, but will host an in-form Arsenal side at Vicarage Road on Saturday evening.
Prodl, who has not played since he suffered an injury on international duty for Austria in September, is again a doubt, while Younes Kaboul remains sidelined.
Andre Carrillo, the winger on a season-long loan from Benfica, could feature for the visit of Arsene Wenger's team despite playing in Peru's 1-1 World Cup qualifier against Colombia on Wednesday night.
"After their defeat against Liverpool, Arsenal have responded in a very good way," Silva said. "The last seven games they have won six and only drawn once, against Chelsea at Stamford Bridge, and they were really close to winning that game.
"They look like a more balanced team and with the ball they have a lot of quality. So, for us, it will be a tough game but that is what we expect against a good team."