Even Arsenal is struggle to beat Fulham in home, they really need Saka, he only play for 7 minutes and can score a goal.
Arsenal ain't a good club without Saka. It's because he is the only player they can rely with. They can play well when he was there, but when he's out, they're clueless about what to do. He's the reason why they're getting very optimistic to fight against Madrid.
I see no better player in Arsenal than him. he's the only one who carried them, and it happens very often.
Saka gives Arsenal the attack they need. Without Saka Arsenal is just defending and cannot do much in attack. When Saka and Martinelli are on the field it gives a huge attack boost for Arsenal. But i doubt they will be able to pass Real Madrid in the champions league.