Evertonian here, figured I'd give you an update on what to expect for the match.
Out Injured: McCarthy, Besic, Gibson, Baines
Out Suspended: Gueye (5 yellow cards)
Last match: Beat West Ham at home 2-0.
Everton's season has been pretty up and down, we have played pretty solidly but there have been too many matches where we just look off and drew when we should have won. Our biggest issue is that we have been almost solely reliant on Lukaku. He is in good form and putting in goals but I think he is involved in like 2/3 goals for us so if he gets shut out then we don't look that threatening. What has been very nice though is our defense has been very solid giving up the second fewest goals in the league behind Tottenham (1 fewer than you and city), so anyone expecting a shootout will probably be wrong. Ashley williams has been a rock on defense and does a much better job organizing us and clearing out crosses (weakness last season).
As far as our lineup this match Baines being out is a downgrade but Oviedo is serviceable and even though Baines is on the downhill we miss his distribution. Having McCarthy and Besic out hasn't been too big of a deal as they are not starting for us but with Gueye out we are now incredibly thin in the center of the park. Gueye has been one of the buys of the summer and for $7M he has been a kante lite. I wish he could play because it would be cool to watch them opposite each other.
Our typical line up has been a 4-2-3-1 If we keep this formation on Saturday we will look like:
Steklenberg
Coleman Williams Funes Mori (Jagielka was dropped due to form last match) Oviedo
Cleverly Barry
Bolasie Barkley Mirallas
Lukaku
I will say Koeman has shown flexibility in his formations and willingness to make changes and drop players due to form or tactics. I wouldn't be surprised to see us line up in a 3-5-2 with Gueye out in order to pack the midfield. Maybe something like this.
Stek
Jagielka Williams Funes Mori
Coleman Cleverly Barry Oviedo
Barkley
Bolasie Lukaku
If you have questions regarding Everton let me know. I actually have a soft spot for Chelsea as they were the first EPL team I saw play live in 2004 when they came to the US and I got to watch Joe Cole tear up AC Milan, plus with my love of DMs, Essien was the gold standard back then as well.