The Chelsea boss endured a tough first season at Stamford Bridge despite qualifying for the Champions League and reaching the Carabao Cup and Europa League finals.
However, Hazard, who is expected to finalize his move to Real Madrid this summer, has thrown his weight behind Sarri over his style of football.
“I think if they can keep the same philosophy as this season, keep playing football like we tried to do it this season, but in a better way – that’s it,” he told Sky Sport.
“When you look at the season they are far better than us, Manchester City and Liverpool.
“If we want to compete with them next season, we need to do it better. It’s that simple. We need to win games in football. If you don’t, you’re in trouble.
“Yes, it is one of my best [seasons] in terms of goals contribution, of course. But at the end of the season, you want to win trophies, so we can go to Baku and win a trophy. If we do that and finish in the top four, it’s still a great season.
“Now it’s like six-and-a-half [out of 10]. If we win in Baku it is going to be maybe seven-and-a-half.”