The Hornets host Leicester City at Vicarage Road on Boxing Day having taken just one point from their last six games.
"In the Premier League we have to work really hard to achieve good results like we did at the start of the season," Silva said.
"Of course, we now have big problems with some players (injuries and suspensions). We knew this could happen with our team and in this moment we need to find the solutions.
"Not only for us. I think for every team, if you miss four, five players from your starting XI, of course it's different.
"We have 25, 26 players and it's the moment for everyone to play and to show [their] quality as well."
Silva admits the morale in Watford's dressing room has suffered during the winless run but called on his squad to remain united until they manage to turn their form around.
"Of course, nobody is happy in this moment. When you win your face is different to when you didn't achieve a good result," he said.
"Like you imagine, in this moment our face in the dressing room is not the best but it's the football.
"Our obligation as a team is to keep all together. I believe and I hope and I'm sure we'll continue all together to change the situation."