Not sure about this. If it's one of those things players often play through then he needs to toughen up. If it's a big mistake that slowed down Martial and Rashford then it's unforgivable from the then management.
But I'm not knowledgeable enough to know.
I'd love to hear from the physios. I remember Smalling also played through injuries and Mourinho even repeatedly questioned the players. Quotes like this make you wonder:
This abrasive style of management has become a regular theme at Old Trafford this season, as Luke Shaw, Henrikh Mkhitaryan, Anthony Martial and a few others can testify, but it was still unusual to hear a manager question the commitment of two players who had the backing of the club’s medical staff and see how aggrieved Mourinho was that Jones, for example, had decided it was out of the question to try to run off a broken toe.
Smalling’s healing process has not been accelerated by Mourinho’s public challenges either and it did not need long in the manager’s company to understand what he made of it. Indeed, there was enough disdain in his voice to merit a follow-up question about whether it might actually persuade him to move out the players in question. Could he, after all, trust two centre‑backs when he had openly questioned their bravery?
He rejected that one but, clearly aggrieved, he also said it was a wider issue for United than merely Smalling and Jones. “It’s not just about them,” he explained. “It’s about the philosophy and mentality around them.”
Asked to elaborate, he chose three words – “cautious, cautious, cautious” – and when he was asked to clarify who, besides the relevant players, he was meaning (the suspicion being it was their agents and possibly some of the medical staff) he hinted again at a culture he did not like. “Cautious … just a cautious approach. It’s a profile, it’s the philosophy of work; just that.”
Mourinho had already stated that Smalling and Jones needed to show more courage, arguing that Marcos Rojo’s ruptured knee ligaments meant it was time “to be brave – to [take a] risk – because for the team you have to do everything”, as well as provocatively insisting that were it himself carrying the same injuries, he would have played through the pain.
It was some statement when Smalling, to put it into context, was wearing a knee brace a week ago but Mourinho’s response was withering again when he was asked whether he suspected the modern-day player was not willing to put his body on the line. “Professional football at a high level – yes.”
https://www.theguardian.com/football/2017/apr/26/paul-pogba-misses-manchester-derby-united-city