The biggest problem is both are desperately out of form.
Other issues is Bruno should never have been made captain, the time when you need your captain is when the going gets tough, Bruno is always one of our worst players in these smashings, the first to lose his head, start moaning, and going around like a headless chicken, he just doesn't have the leadership qualities to be captain, and it was obvious before he was even given it, because it's not like this isn't something we've seen half a dozen times before.
Rashford has been built up to be like "the man" at the football club, but the reality is he's never shown he's good enough to be on such a pedestal. His entire career has been one of peaks and troughs. He goes through patches where he'll score 10 in 10, then plays crap for several months. One of the issues is fundamentally he has a lot of flaws, which are more apparent when his output is so low, people are more willing to put up with the lack of work rate if you're scoring every game, less so when you're scoring 1 in 10.
They aren't going anywhere though, and people are kidding themselves if they think either is going to be moved on anytime soon.