IAN LADYMAN: Trent Alexander-Arnold was one of Liverpool's best attacking outlets in the Champions League final... but then he was caught out for Vinicius Jr's winning goal, which exposed his defensive flaws

• Real Madrid lifted the Champions League for the 14th time by beating Liverpool
• Vinicius Junior scored the only goal of the game just before the hour mark
• The young Brazilian arrived at the back post to finish Federico Valverde's cross
• He caught out Trent Alexander-Arnold, whose defensive fragilities were exposed
• Going forward, the full-back was one of Liverpool's most threatening players

A rare break down the right side, a cross shot from Federico Valverde and there he was at the far post drifting off Trent Alexander-Arnold’s shoulder to score. The young Brazilian, Vinicius Junior. It was impossible to say that Liverpool, and Alexander-Arnold in particular, had not been warned.

Vinicius had troubled the Liverpool right-back before, when Real knocked Liverpool out of this competition last season. Since then, he has got better. Against Manchester City in the semi-final, he had been terrific.

Alexander-Arnold had been asked about his immediate opponent in the run up to the game and had replied by saying Liverpool would defend as a team. What else would we expect him to say?

More widely, though, the 23-year-old has had to listen to questions about his nuts and bolts defending for a while. He has been accused of switching off at key moments. Certainly it’s hard to say there was no evidence of that here.

Replays of a goal that came against the flow of the game showed the scorer probably six inches from being offside. Also, they showed that Alexander-Arnold was on his heels fractionally as the ball came across. It would not be fair to say the goal was his fault. Not everything that goes wrong for a football team has to have a culprit at the core. However, could Alexander-Arnold have done a little better? Possibly.

It was shame, too, as he had been terrific up until that moment. With Liverpool having so much possession and territory, Alexander-Arnold had been one of his team’s most effective outlets. It was easy to see here how Alexander-Arnold prefers to play this game.

Often he would push himself ahead of the Real front three when his own team had the ball, in an attempt to join with Liverpool’s attacking play, or at least make himself available if the ball needed to come deep to be recycled.

This is sometimes what can catch him out. Jurgen Klopp and the Liverpool manager’s staff rail at suggestions that the player they have done so much to develop cannot defend, but it is not his first instinct.

Occasionally he can be blind to what may be about to happen over his shoulder, and there were instances of that here even before the Vinicius goal.

This is when his relationship with his team-mates is indeed important, particularly with the central defender on his side. Last night it was the young Frenchman, Ibrahima Konate, selected in what must have been a narrow call ahead of Joel Matip, and a couple of times Konate was there for his team-mate as Vinicius found a way in to the pocket behind the Liverpool full-back.

On another occasion, the midfielder Thiago Alcantara read the danger to drop in and take the ball from Vinicius’s toe in the penalty area after he had somehow managed to squeeze through a gap between defenders. When managers talk about their teams defending as a unit, this is what they mean.

At the other end, Alexander-Arnold was a menace and this is exactly how Klopp likes it. As Liverpool dominated possession and territory with startling ease, Alexander-Arnold was largely free to play as an extra attacking player.

His first contribution of note was to take possession from Jordan Henderson’s lay-off in the Real penalty area and feed the ball in to Mo Salah. The Egyptian’s low shot brought the first of several good saves from Thibaut Courtois.

That was not the first opportunity created for Salah by the full-back. A cross from the right was accurate enough in the 34th minute for Salah to head towards goal. This time, the ball landed in Courtois’s midriff.

Earlier, Alexander-Arnold had arrived with clever timing to drive a shot of his own over the bar. His delivery from set pieces was as accurate as it usually is. In the opening moments of the second half, meanwhile, a superb first-time cross looked set to be headed in at the far post by Luis Diaz only for Dani Carvajal to apply enough pressure to put the Colombian off.

For the first 45 minutes at least, Real had not been ambitious enough to trouble the Liverpool back four on a consistent basis. Against Manchester City in the semi-final, Vinicius was allowed to run from deep and at pace with the ball. This was what caused Guardiola’s team so much trouble, particularly in the first leg at the Etihad Stadium when the quickness of the injured Kyle Walker was absent.

Here, Vinicius really had not hurt Liverpool until the very moment he did. And by the time Alexander-Arnold and his team-mates realised, it was too late.