Fish, 21, was booked for his reckless challenge on Liverpool winger Harvey Blair but ended up coming off worse in the exchange. Ten Hag spoke to Fish while on the stretcher, with the young defender looking distraught with the new season just two weeks away.
Fish has spent his entire senior career at United, but has only made one first-team appearance. They have beaten Rangers and Real Betis, but had already lost two key players to injury before Fish was carried off on Saturday.
Hojlund is expected to miss six weeks, while Yoro could be ruled out until October meaning he will miss the opening months of the new season. Ten Hag would have preferred a more positive performance from United heading into the game against their arch-rivals, but is now tasked with putting Saturday’s game behind them.
Fabio Carvalho put Liverpool ahead within 10 minutes after beating Casemiro inside the penalty area with a quick change of direction, and Curtis Jones doubled their lead before the break. Kai Havertz pulled one back for Arsenal, but Liverpool held on.