Play Bernardo or Diaz as a false 9, or play Nmecha in some games. This isn't as bad as people make it sound, Sanchez would have only been useful in regards to the Champions League, But if Sane has to play those games, which is only like 6 or 7 games max, it is really easy to play one or two youth players in the league, because we have that wrapped up anyways.
Basically, it's not a problem, buy a DM for Dinho down the line (Fred I guess) and that's it. We don't even need a LB, you don't buy because of injuries, everyone being fit we would have Mendy, Delph, Danilo and Zinchenko (sort of) at LB. The injury to Delph means Danilo will play more (and Zinchenko) and he does fine there.
If we desperately need another forward, then Dybala would be the best suited player for Pep.