If this team has Maxi available to go most of the match in the midfield, they’ll be fine.
Yes, Taty is a big loss, but it’s clear that this team can’t survive without either Keaton or Maxi in the midfield. They need someone who can possess and progress the ball as well as orchestrate building up from the back. Santi is great at the 10, but he isn’t as great at maintaining possession, or drawing in defenders to then dribble past, or 1-2 passing to open up more options.