Manchester United head coach Erik Ten Hag has said "it wasn't the defending" that led to his side's opening-day defeat to Brighton and Hove Albion at Old Trafford.

The Seagulls found themselves 2-0 up at half-time after Pascal Gross scored a first-half brace to put his team two goals to good at the interval.

Ten Hag had opted to leave Cristiano Ronaldo on the bench due to a lack of fitness, but brought him on in the second period to positive effect and an Alexis Mac Allister own goal set up a tense finish.

Brighton held on though for their first ever away win at Old Trafford, condemning Ten Hag to defeat in his first competitive game in charge of the Red Devils.

However, the former Ajax man refused to blame his backline for the defeat, telling reporters: "It wasn't the defending. We defend as a team and we made passing mistakes that were unnecessary in the midfield, then they took over. 

"We have to be better at organisation because we have made appointments and they have to do the job which we talked about, which they have been appointed to do. That is not what we did and then we got punished.

"The same with the second goal, it was totally unnecessary from a ball that was loose in the corner on the other side. It is not good that you then go on and concede a goal."

Ten Hag also spoke on the improvement in United's performance after Ronaldo entered the fray, while conceding that he still has a way to go until he is at his best.

"It was clear to see that in the second half we were better in the midfield, with Christian Eriksen back down and Cristiano Ronaldo further up," Ten Hag added.

"Then we create and [Marcus] Rashford had two really good chances and it's a pity we didn't score to make it 2-2.

"It takes time. We cannot force it and one week in training, a little bit more now, he has to do more to get fit and this game will help him. The 35 to 40 minutes he had now and now we have one week and he will be better next week."