Earlier in the game Sagna had made a run half or third the length of the pitch, against Erik Pieters I think it was, and beat him for pace. So it's more about the number of times the older players have to run that shows them up - keep possession in the middle or up front and they do less running, obviously. You see this in 100M sprinters who can still compete at the very top well into their 30s.
The issue we have is that our system relies on possession and intelligence in the defensive midfield, of which we are doing neither at the minute.