Thomas Tuchel wants his team to secure a top-four finish.
The Blues beat Leicester City 2-1 on Tuesday night and moved into the third place of the Premier League table.
In that game, Timo Werner had two goals disallowed by VAR.
“It’s his job to be involved in everything and he needs to be involved on Sunday,” Tuchel said after the game.
“There is no time now for extra praise, it’s time to enjoy and then shut up.
“Enjoy your free day and be ready for Aston Villa and nothing else.
“I don’t feel comfortable celebrating now – for what? I’m not worried, I just say what’s needed.”
Tuchel added: “It felt like a huge effort and a top performance.
“Don’t get me wrong, it’s a big step but it’s only a step, it’s not done yet.
“We have to get over the line on Sunday.
“It was a team effort full of intensity, full of hunger and ambition. We played many, many minutes with a lot of quality.
“It was in my opinion a well-deserved win but it’s not the time for praise and celebration. It’s not the time about philosophy and whether this is more than three points.
“There’s another game to catch on Sunday we’ll be prepared and aware to finish the job.”