The 31-year-old midfielder played 60 minutes of Chelsea’s Community Shield defeat to Manchester City but was not available in Saturday’s win over Huddersfield Town due to knee problem.
Sarri also confirmed that midfielder, Mateo Kovacic was available but disclosed that the Croatian would not be able to manage the full 90 minutes against Arsenal.
“Fabregas is out for this match,” Sarri said ahead of his first Premier League home match as Chelsea manager.
“I hope he will be able to be on the pitch in the next week, but I am not sure. It’s nothing serious but he has a very unusual injury.
“It’s nothing serious. I hope in the next week he’ll join in training. He has a pain near the knee, not the knee, but near it.”
The Italian was confident that Unai Emery’s men have a “competitive” season under the coach.
“I think that Emery is a very good coach. He won the Europa League three times and he won in France with PSG.
“I think Arsenal this season will be competitive. I think they’ll be able to fight for a place in the Champions League.”