Chelsea had won all five of their league matches before the weekend, going toe to toe with Liverpool, who beat Southampton on Saturday to make it six wins out of six.
"I don't know. For an English team, the Europa League is a very hard competition".
Sarri also refused to use Europa League fatigue as an excuse after Chelsea's ideal start to the season ended.
Finally, asked about how his vision of "Sarriball" is coming on, he said: "We need to move the ball quicker I think".
"It's important for me to showcase my talent, obviously a year ago I played in defence and now in midfield, I'm just cherishing it".
However, the Blues have started the season well, winning their first five Premier League games and their opening Europa League group match, before Sunday's draw with the Hammers at London Stadium. Then, I think that we have played very well. well in the second half, generally, but very well in the last 25 minutes.
In the absence of Marko Arnautovic, Michail Antonio and Andriy Yarmolenko squandered golden opportunities to turn one point into three in the 0-0 draw at London Stadium.
Chelsea need their superstar to start thinking more like a wide forward and less like the winger he has always been if they are to avoid more days like this, particularly if Pedro's absence proves a lengthy one and goals continue to elude Morata and Giroud.
"In Naples, the beginning was very hard".
Yarmolenko seems to be taking the joke in good humour, with the video captioned "about last game" with three laughing-crying emojis, and he can be heard chuckling off-camera.
The latest stories in the rivalry will be written this week as the two sides clash twice in under 72 hours, firstly in the Carabao Cup and secondly in the Premier League.
One man who central to West Ham's defensive resolve was Declan Rice. I don't know in the future.
I see Declan working every day and I know the way he does it.
Information from The Associated Press was used in this report.