I think EtH's long-term plan is to go with:
Onana
Mazraoui De Ligt Martinez Shaw
Ugarte Mainoo
Garnacho Bruno Rashford
Hojlund
As his first choice XI. However, given Shaw's injury record it is probably optimistic. Dalot will probably end up featuring purely because he is continually fit. Yoro could replace De Ligt depending on performances and fitness when he returns, but I think the plan might be to have Yoro & another young CB in the near future as the squad options behind that first choice CB pairing (maybe Branthwaite if previous links were true). Will Rashford ever be able to recreate his good seasons? He's a player who has had probably a couple of good seasons for us, and a couple of awful ones, with some average ones in-between... This to me says the average ones are his usual level. If he could get 25~ combined goals/assists a season I think everyone would be content with him as long as we have a striker scoring 20+ and Bruno is hitting his standards.
I'm not sure how long it will take for EtH to have this XI consistently available - it obviously won't be this game against Southampton. But maybe he could sub on Shaw, Ugarte, and Hojlund if they're ready? Personally, I think Rashford needs dropping as well and just start Amad & Garnacho either side (of probably Zirkzee on Saturday). However, I think EtH is likely to start Rashford because he will probably be the freshest/fittest choice at this time. If we aren't winning games over this period before the next International break, I think he'll be very lucky to still be in the job.
Onana
Mazraoui De Ligt Martinez Dalot
Casemiro Mainoo
Garnacho Bruno Rashford
Zirkzee
I think that's what I'm expecting him to go with. I hope we win, and I think we'll probably sneak it 1-2. Result is paramount, but they'll still be concern if we don't win well.