Antony was never going to stay on the high of his debut against Arsenal last weekend, but such a drastic dip in performance level less than a week later in a 1-0 loss to Real Sociedad was nonetheless jarring.
The Brazilian newcomer and Cristiano Ronaldo were among the lead culprits in the deflating Europa League outcome Thursday, reminding Ten Hag of the work he still has to do.
David Silva came back to haunt the Red Devils - albeit in controversial fashion - as the ex-Manchester City star won a second-half penalty when his shot struck the arm of Lisandro Martinez. Brais Mendez then stepped up to convert from the spot.
Manchester United had won four games in succession in the Premier League.
Now they can see that it'll be a process to embed Antony into their system, while they face fresh questions over whether Cristiano Ronaldo can thrive under Ten Hag, with the 37-year-old failing to convert two gilt-edged chances.