The Argentina winger, who was subbed at half-time of last weekend’s 2-2 draw at Bournemouth, liked two messages on X(formerly known as Twitter), which were negative about his gaffer.
He quickly unliked both posts and has now begged pardon, leaving no issues around his involvement for this weekend’s FA Cup semi-final against Coventry at Wembley.
Asked whether it suggested the group was not together, Ten Hag replied: “I wouldn’t point to that.
“Alejandro is a young player, has to learn a lot. He apologised for it and after that we move on.”
Experienced midfielder Casemiro has received criticism for his recent performances, with Sky Sports pundit Jamie Redknapp suggesting his display against Bournemouth last week was like he was playing in Soccer Aid.
But Ten Hag has backed the Brazilian and insisted he will bring United success.
“I think we needed the six when I arrived here and last season Casemiro was fantastic,” he said.
“I don’t think he ever scored so many goals as well but as a six, a holding midfielder, as a strategist, he was so important for the team.
“This season he struggled with a bad injury he never had in his career, but he is such a winner. See his career, always in his career he has won, everywhere he was there will be success.
“I trust he will give us success and I know he will need games and he will be better and I’m very confident about him.
“He is a fighter, why he also won big trophies, he’s a personality and he’s a very important player and he will give us success.”
Another player who criticised the club on social media was Jadon Sancho and the winger has since found his form on loan at Borussia Dortmund, who made it through to the Champions League semi-finals this week.
Ten Hag said nothing has changed surrounding his future because of his performances in Germany.
“We know Jadon Sancho is a fantastic football player, so that is not a surprise for us, that is not the issue,” he said.
“Of course, I follow international football and follow the players on loan at other clubs.
“It was a fantastic game, Dortmund against Atletico Madrid, great performance from Dortmund and for Jadon it’s good news. He made his contribution to the result for Dortmund.”
Ten Hag hopes to be able to have Scott McTominay and Antony back in the squad against Championship outfit Coventry on Sunday.
“Antony and Scott I expect them to be back,” he said. “Scott didn’t train all week, partial on Wednesday, today I expect him full. Antony did train all week.
“We have some problems. Harry (Maguire) had a small injury, he didn’t train this week so far but now he is back on the pitch. We expect him to be back for Sunday, I hope.”
