There is a reason why Sakho doesn't start much for PSG; it's because he's not that good.
Sakho is not bad but is not a crack. He was used to do good matches but almsot each time he made a mistake, we conceided a goal.
He was competing with Alex to be in pinch but TS stated he was more comfortable with Alex since they are both brazilains and Alex has more experience.
But as he was not really a starter, he was the one who played most due to several injuries.
I think he improved this year, commited less faults, being more reliable.
PSG don't want to let him go but he absolutely wants to be a starter and i don't think any big clubs can make him the promise he'll be. So he should think about this.