He's only played more games in one other season I think. So it was as full a year as any pro can expect with injuries etc. Him doing what he did whilst 35 doesn't get us additional points so ultimately who cares what age he was.
In anycase the desperation of Mourinho to get him in the team was sadly predictable. No problem with him being an option but jamming him in when there's no real position for him, when he's not fit, when He's no long term future here. What's the point?
He doesn't have to have a long term future here. He didn't have one last year as well and still knocked in 28 goals as a 35 year old. The age is relevant since that simply doesn't happen in England.