But his latest jaunt to Northern Ireland throws all that out the window. He doesn't care - not about the club or his profession. Rashford is clearly unwilling to do what's needed to fulfil his potential. He wants it all - without the sacrifice. And as we say, for such personalities, United can no longer carry them.
United need grinders, obsessive workaholics - in attitude and approach. They need men who are 'all in'. Who understand the reality of where the club is and what it will take to get it to where they all want it to be. Rashford simply isn't built for such a purpose.
He's undermined his manager - again. The odd birthday bash can be excused but he did it last season, sleeping in - a grown man failing to roll out of bed at the required time. And now we have Belfast.
Again, we'll give him the benefit of the doubt. Two nights out. The cynics will say he came back worse for wear. But let's say he did return home having picked up a bug, so he misses Friday's training. It's stupid and unnecessary. At 26 years of age, this isn't the stuff of a serious pro.
Rashford will be 27 in October. Are his best days behind him? Only he can tell us how spending midweek partying in Belfast benefits his football. Or more importantly, how it benefits Manchester United.
The latest episode shows that Rashford has undermined Ten Hag. He's challenged his authority. But the manager is an easy target. This goes beyond the Dutchman. Just weeks into this new era, investor Jim Ratcliffe already has a problem - the local lad of all people. The player so much has been hoped for. He's acting up. Breaking, if not team rules, then certainly the team culture. This is Ratcliffe's first problem. Will he sit back and let others deal with it? Or will he get in there himself to sort things out? Again, given the timing, this has been a really stupid act by Rashford.
Indeed, for this column, it should be his last chance as a Manchester United player. With Financial Fair Play still an issue, it's no secret United need a big sale. There are plenty of names being put forward: Casemiro, Raphael Varane, Aaron Wan-Bissaka... but Rashford must now be under consideration. Or better yet, with this act, he's effectively put himself up for sale.
Two years into his reign, Alex Ferguson took on the Stretford End by selling one of their own - Norman Whiteside. He was Northern Irish, sure, but he'd come right through the United system. The fans had seen him break records for club and country. He won an FA Cup on his own and scored spectacular goals (that turn and strike against Clough's Forest still a great memory).
But Whiteside just didn't have what Fergie needed in a United player at that time. Far more talented than Rashford and much more loved by the support, Whiteside was still sacrificed and sold to Everton. It was a difficult decision, an unpopular one, but one that needed to be made.
Thirty-four years on, Ten Hag faces a similar situation with Rashford. Though we will say, nowhere as difficult. Again with Whiteside, we're talking about a player who rejected a fortune from AC Milan out of loyalty to the Stretford End. Such ties don't run anywhere as deep for Rashford.
"If you want to perform, you need hungry players," declared Ten Hag.
"We need personalities and players who are very hungry to fight for the badge and this club.
"It is not about discipline, it is about normal behaviour. It is about what you can expect from a top professional."
That was said not today - but exactly a fortnight ago. Rashford really has made up everyone's mind, hasn't he?
At 26 as a senior player and leader, last week's actions were not fitting of a player of his status. He just doesn't have what Manchester United need at this time in their history. Marcus Rashford needs to be sold.
