I really don't understand all these 'injury prone' comments. The lad has had two big injuries in his time with us. That's luck, not being injury prone. Same can be said with Gundogan.
Delph, Kompany, Aguero have been plagued by constant niggles and injuries throughout their career, THAT was injury prone. Luckily all three seem to be managed much better than in the past and put that behind them.
I feel for him as I tore my left ACL and meniscus in June, on my first training session back of pre-season. Absolute fluke, I rolled my foot over the ball, it slipped under me and I landed full weight on my other leg. I've been plagued by niggle of my right knee since I was in my early teens (it's been somewhat injury prone) but never had an issue with my left knee. And now I'm waiting on a surgery date after 3 months of physio to get my strength and range of motion back.
We have excellent cover (Delph, Zinchenko, Danilo, Laporte or we can play 3 at the back) and a manager who will always adapt his tactics to the available squad. We're fine.