Without being told, Ten Hag has a lot to work on this time. I don't see Manchester United going far with the current squad. If nothing is still not done, sign new players and let the old ones go. Ten Hag will be the one to blame not the players afterwards, if Manchester United didn't appear at the top of the table again. That could even lead to his sack as being an incompetent coach who can get his team players in good playing positions to top the PL table.
I don't know whether Ten Heg needs to be reminded again that, he will be the only one to be held responsible(not the management of the team) if Manchester United doesn't perform well again. However, for Ten Hag to avoid a sack not to happen towards him, he should do the necessary thing by telling the Manchester United management to sign new players and let go of the old ones, if they want the team's performance to be good compared to last season
Good thing that he is facing this issues now, I think Manchester United will still be much more active this transfer windows especially from the fact that Rasmund and Yoro who they just recently signed where injured in the friendly match against Arsenal, with Yoro injured and Martinez past injuries record it is obvious they will have to sign more Cb while they already going for another Rb since Aron Wan Bissaka is open for sale.
I think Ten Hag will be spending much still to improve his squad though it will be quite Ironic if he fail to at least get to EPL top 4 or win a better trophy possibly the Europa league. Though I`m thinking if United won`t consider getting a competitor for Onana as main goalie.