Watford manager Vladimir Ivic believes his side can play better, despite an impressive 4-1 victory over Preston.
An inspired performance by captain Troy Deeney, making his first start of the season, contributed to a comfortable performance.
Watford are currently third in the table, but Ivic thinks his side have room for improvement.
He said: "It was one of the best performances of the season, today I believe we had a good game. This was not our best performance.
"This is our target, to play better and be able to play every game like this, to improve some details during the game.
"When we have games every three to four days, we need to take care of a lot of things, not just the games.
"When you have a lot of injured players you need to be smart in how to use them.
"I could speak about Troy Deeney and his quality, and how he's important for the team, I don't think it's a doubt.
"He did his job today, it's the first game he's started and I expect he'll be available in the next games to help us."
The lead was doubled eight minutes after the restart from the penalty spot when Sarr was upended in the area after a challenge by Jordan Storey, and Deeney stepped up to mark his return to the starting line-up with his first goal of the campaign.
Preston manager Alex Neil thought his side, while ravaged by injury, was let down by poor defending.
"It was always going to be a difficult game for us, if you look at Watford's squad coming down from the Premier League, they're full of quality players," Neil said.
"If you look at what we've got missing at the moment, we don't have a fit full back four or even cover for one.
"To be honest I thought it was a good competitive match for sixty minutes and then we just don't defend some basic stuff in the box well enough.
"When you give Watford goals quite cheaply, you find it doubly difficult to get into the game.
"As soon as the fourth goal goes in, the game is over at that point."