Ten Hag cancelled their day off after defeat at Brentford to haul in the players for a Sunday morning debrief.
The Mirror says during the emergency get-together at their training headquarters, Ten Hag is believed to have laid down the law to a team that has started the season with defeats to Brighton and Brentford.
Unsurprisingly, Ten Hag said the performance against Thomas Frank's side was unacceptable.
The players themselves are also believed to have had clear-the-air talks after exchanging angry words during the match and in the wake of the embarrassment in London.
Ten Hag was still horrified by events at Brentford, which he described as “rubbish".
According to United sources, 'read the riot act' to his underperforming stars.
Ten Hag is also scheduled to have talks with CEO Richard Arnold and football director John Murtough amidst continuing frustration in the transfer market.