I've just realised that's the first time I've seen Musacchio play this season.
For people who don't remember the incident, he broke his leg and dislocated his ankle, a horrible looking injury with blood as well as some really oddly angle limbs in the photos that followed. It was a similar but uglier looking injury than the one Luke Shaw sustained. In fact it looked like the kind of injury where you hope the player is still walking normally after. He was injured April 11th, and restarted normal training at the end of September. 8 months total from injury to starting.