We need to start the trio Vecino-Gag-Valero this game:
Padelli
Cancelo-Ranocchia-Skriniar-Nagatomo
Vecino-Gag
Karamoh-Valero-Perisic
Icardi
Padelli
Cancelo Ranocchia Skriniar Nagatomo
Vecino Gagliardini
Candreva Karamoh Eder
Icardi
If I had to guess
What the hell happened to Perisic? He looks completely impotent. He looks both unwilling and unable to beat his man and deliver crosses (which he did with complete impunity right up until the Chievo match) and his overall involvement in recent matches has drastically decreased. That means 80% of the attack goes through Candreva (also playing terribly) which is fucking infuriating and part of the reason he was so ineffective and criticised to begin with.
Honestly I think match fitness might be getting to us
Spalleti didn't properly rotate for most of the first part of the season. Perisic, Icardi, and Skriniar played an absurd amount of minutes this season (same with Candreva and Valero to a lesser extent)
Aside from Skriniar, all of these players have been seriously underperforming as of late and I highly doubt that's due to chance.
It's a shame that even without Europe our squad depth isn't sufficient. The only place we really have first team subs is in our midfield, which I think is only because it's the weakest part of the pitch (besides LB and RB)
Is it really an absurd amount of minutes? 18 matches in 4 months? We have no Europe to worry about, without looking at stats I would guess that Dzeko, Higuain, etc. have played more minutes than Icardi has. I don't think asking them to play 1 match a week is really all that demanding.
More squad rotation would be nice, but like you said our squad depth isn't sufficient. Juve can lose half a dozen starters and still throw out a capable squad. If we lose any 1 of Icardi, Perisic, Skriniar, Miranda, etc. then we're screwed