We can't just go and get a new player every time someone gets an injury, especially at the level we want. What do we do with these players once everyone's fit again? We have plenty of options to work with and can still rotate without him. Sure we'll be poorer for not having him, but bringing in someone inferior to what we already have won't fix that. Silva, Navas, Sterling, Iheanacho, Toure = 5 players for 3 spots. Whilst I prefer them in the holding positions, Delph and Fernandinho could probably do a job somewhere in that if absolutely required, plus we also have youth players to call upon if needed. That's what everyone else has to do.
A loan could be a maybe but I can't think of anyone that good who's available.
