Conte has a few interesting decisions for this one
1) RWB... Surely Doherty is favourite, as long as he's fit enough. If not, then Emerson. Probably too soon for Spence. Missed a bit of pre season and Conte won't throw him in until he's physically, tactically and mentally ready. Lucas I think will be used at RWB mostly as an attacking sub, a useful option with the 5 sub rule.
2) LWB. Perisic to start if fit. Knows Conte's system inside out and is the clear first choice.
3) LCB. Sanchez did pretty well there against Rangers, but Lenglet offers much more in the buildup, so should start assuming Davies is out.
4) Midfield. Really not at all sure what his thinking is on this. Surely we want Bissouma in there for Chelsea, so would make sense to bed him in against Southampton. Biss-Hojbjerg got minutes last week. I like Biss-Benta but wouldn't be surprised if he sticks with Benta-Hojbjerg for this one to avoid too many changes.
Lloris, Doc, Cuti, Dier, Lenglet, Perisic, Bentancur, PEH , Deki, Kane, Son