Ronald Koeman said that he "protected" Matthijs de Ligt by substituting him at half-time of Netherlands' 2-2 draw with Germany on Tuesday after the Manchester United defender's struggles on the international stage continued.
De Ligt was at fault for Joshua Kimmich's goal on the stroke of half-time after he gave away possession in his own half. He also bore some responsibility for a missed tackle ahead of Germany's first goal.
The 25-year-old joined United from Bayern Munich on Aug. 13 along with full-back Noussair Mazraoui. Sources have told ESPN that the deal was worth a combined £60 million ($76.6m) including add-ons.
"You'd rather leave a player on the pitch. But I protected him," Koeman told Dutch broadcaster NOS. "I don't think the moment would have left his head for the rest of the game. He's in a phase where such a mistake gets punished right away."
De Ligt was also criticised in the wake of Netherlands' opening Nations League A Group 3 match against Bosnia in Eindhoven on Saturday.
He was caught on the wrong side of the ball, allowing 38-year-old veteran Edin Dzeko to score, although the Dutch went on to win 5-2.
"We have discussed it," Koeman told a news conference ahead of the Germany game at the Johan Cruyff Arena.
"He did not get his footwork right. It was a bad individual moment for a defender. You have to learn from that, it is clear that these kinds of moments need to be improved. But we should not be dramatic about it and put too much emphasis on it."
De Ligt, who made his first start for United in their 3-0 defeat to Liverpool before the international break, acknowledged his error and his lack of form for his country.
"I didn't feel like I was quite able to get my steps right and I heard something, which made me think the goalie [Bart Verbruggen] was coming, but I don't want to put the blame on him at all," De Ligt said. "I'm doing my best, but I know it can be better."
Koeman said on Monday he hoped the move to Old Trafford would ensure plentiful opportunity for De Ligt, who started only half of Bayern's Bundesliga fixtures last season.
"I also spoke to Koeman about my transfer to United. I'm very happy with it," De Ligt told NOS at the weekend.
"It's also to stay in the picture a bit more, as crazy as that may sound. But you do notice that the Premier League is watched by everyone and the Bundesliga apparently less."
Information from Reuters contributed to this report