I don't know what exactly you have against him, but he had a fine game. He created a few great chances - one at the start of the second half, when he played in Lukaku in the centre of the box, also the one where Lukaku tried to go around the keeper. Those were perhaps the two best chances we had and he played the last pass. He didn't get a goal and perhaps should have done better when alone in the box and he missed the goal badly, but he was good. He also did his defensive duties very well(which is expected, but not everyone does that job with as much energy and manages to be as clever about it).
I don't have anything at all against Rashford. I like the kid and think he is a huge talent, but I am against the hype which is dictated by the media and some of our ex players. In my opinion, all of this can harm a growth of a player that could be an asset for the club in the next 10 years or so.
I think Rashford should not be overplayed and should be kept with his both feet on the ground. It is easy for a kid to get carried away by all the hype and start thinking he's a superstar.
Talking about yesterday's game, he did have a couple of good passes to Lukaku, but that's about it. He made lots of mistakes and you could see there is fatigue and lack of concentration. In this case, it is for the best of the team and player himself to sub him off. Imo, nobody should be immune to substitution or starting a few games on the bench. It could even do good sometimes.
Hope that I made my views clearer.
Concerning Fred, I feel for him and I agree we should give him chances as he is starting to show some glimpses of a valid player, but he must quickly grasp a few things about Premier League. If he doesn't get used to the pace of the game in EPL and to the short time on the ball that midfielders have at their disposal, he won't have a bright future at United.
Things are not going so well for him atm, but I still have some faith, even though I would not bet on him becoming our firm starter anytime soon.
Lindelof - in this game he went back to the player we've seen under Mourinho. Seemed completely lost in several occasions. Must do better to keep his place.
Young - not his fault that he is always used out of position (he is a winger after all), but everyone have seen he's often a liability in defence, so any valid opponent will exploit our weakness on that side. It's not only about yesterday's game, but talking in general. It would be OK if he was just an urgent solution, but we've made him our standard starter and it's just wrong. It is like you have a bad tooth and you continue taking medicine against pain, instead of fixing it. Given the current situation, I think we should give some more trust to Dalot until the end of the season. This will show us whether he is good enough or it is necessary to dip into market for a right back. Continuing with Young as a firm starter won't get us anywhere.
Back to our loss against Arsenal, it was a bit unlucky, but it's up to us to use the occasions and to maintain concentration in defence. Anyway, we should not make a fuss about it, as we knew a defeat would come sooner or later. There will be a good fight ahead of us for the top 4, so the players should be further motivated by such challenge.