Whilst it is great to see any player under Mourinho falter, it makes it even sweeter when he's poached one of our top stars and said player has been floundering in the wilderness. I do take a lot of glee from this situation.
However, let's not forget that Sanchez is still a top-class player and he was our (joint) top goalscorer before he left, alongside Lacazette. Even if he stayed and didn't score any goals for the past two months, he would still be our top goalscorer, which shows just how badly we have struggled in front of goal at times.
Contrary to a few of the comments on here, I still maintain that a player of Sanchez's quality would be beneficial to us and would have been a game changer in some of the shocking displays we've seen over the last month or so. He was a get out of jail card for us. We don't have one of those any longer.
There are a triad of reason why I believe he's been ineffective at United.
1) He is unsure about what his actual role in the team is. It isn't clearly defined. Is he supposed to create? Is he supposed to be a more potent goal threat? What areas is he meant to be operating in? What's the position which their team can get the most out of him? A lot of these questions remain unanswered and I don't believe Mourinho has helped by shoehorning him into the team.
2) At Arsenal, he was the star man in a team with very few star players. Now he's in a United dressing room full of egos and strong personalities. Perhaps he has struggled to accept that he won't be the centre of attention like he was at Arsenal.
3) Although we get criticised for getting too exposed, we did have a lot of midfield runners in our team, thus giving us more attacking options. The midfield at United aren't on his wavelength. He's gone from a midfield that isn't disciplined enough to a midfield that is too disciplined. Whenever he loses the ball, he is expecting more support from the players behind him, yet because Mourinho curbs their attacking instincts, he has less options to utilise.
As I said, I am quite smug about his woes at United, not least because of who their manager is. But if we still had him in our team right now, with the way we play, he would be an asset to us. Think about it. He was determined to leave us and wasn't a positive influence, yet his contribution in his last few months still outweighs 98% of our squad.
I genuinely think if United had a more forward-thinking, progressive manager, he would be performing significantly better than he is right now.