They've slid down the table to 11th, a long way off the pace for a Europa League position.
'We started to defend in a very good way in the last month, I think.
Even though Higuain is set to be available for selection at Goodison Park this weekend, Sarri may well decide to give Giroud a first Premier League start of the year following his impressive performance in the week.
Football news - Arsenal draw Napoli in quarter-final, Chelsea to face Slavia Prague
"So, for me, it will be very hard to play against them in Naples".
Olivier Giroud's flawless hat-trick away at Dynamo Kiev took his Europa League goal tally to nine, the highest in the competition so far. Physically, technically, he is improving tactically.
Hudson-Odoi continued his eye-catching Europa League campaign with a goal and an assist at the Olympic Stadium, and Sarri was encouraged by the 18-year-old's display - while sounding a familiar note of caution.
Hudson-Odoi also continued his fine run in the competition with a fourth goal in Europe this season and while Walker thinks he will only get better, Giroud could act as the flawless role-model for him.
Arkadiusz Milik scored a crucial away goal in the 14th minute to all but end the tie, leaving Salzburg needing five unanswered goals to progress.
The 19-year-old Magomed-Shapi Suleymanov's 85th-minute effort looked set to dump out the Spaniards on away goals, but Portugal global Guedes came off the bench to send Valencia through. They've got a real chance of the top four.
Brextension: UK lawmakers vote to seek delay of European Union departure
Last night, Members of Parliament (MPs) voted by 312 to 308 to reject a no-deal Brexit, which sent the pound soaring to over 2% . The EU has done "all that is possible to reach an agreement" and the solution to the deadlock "can only be found in London ".