This is why I am sure Saka returning won't matter much. They didn't do terrible without Saka, so they saw that they do not need him all that much, sure it's cool to have him, but not like they were losing games all the time when he was out.
Plus, Liverpool is doing awesome right now, and Salah is doing amazing as well, so that means as long as Liverpool keeps doing this great, we are not going to see Arsenal win, no matter who they have. Arsenals fate is not based on what Arsenal does, they can win all the games, their fate depends on Liverpool and how they do, if they do well then we are not going to see Arsenal catch up. This is why no matter if Saka returns or not, we are not going to end up seeing Arsenal win, as long as Liverpool stays great.
This is just another fact, in as much as Gunners needs to try to get as many of the 3 points they can get, they also do hope Liverpool do drop enough points to top them which likely may be difficult as things are now.
Also I think while Saka returning is a good boost, Kai Havertz just got injured during their training in Dubai and the extent of it is still unknown. I wonder who will be playing nine for them now since their main attackers are all sidelines at the moment.
https://www.google.com/amp/s/www.dailymail.co.uk/sport/football/article-14386141/amp/Arsenal-injury-Kai-Havertz-Gunners-Dubai.html