He subbed Oscar in this particular game because he was on a yellow, but was still flying around and making tackles. He had also already gotten Ibra sent off, and the PSG players clearly would milk any fouls he committed. Overall, it was one of his better games since January. I don't think he'll leave though, Mourinho claimed he can make a big evolution next season and has always supported him since he returned. Oscar also does not cry when he's left out, and i'm sure Mou likes that about him.