The Champions League is already giving Manchester United clues about transfer targets

Maybe wing-backs are making a comeback. Ruben Amorim's three-man defence is yet to catch the imagination at Manchester United, but elsewhere, there is evidence that the system is capable of delivering teams that challenge at the very top.

On Tuesday night, Simone Inzaghi's Internazionale reached a second Champions League final in three years after winning perhaps the greatest semi-final the competition has ever seen, beating Barcelona 7-6 on aggregate after two games of the highest quality.

Inzaghi might just be the most under-appreciated coach in Europe, and steering this ageing Inter side to another shot at the European Cup is a remarkable triumph. Matteo Darmian still gets games on a regular basis, and Henrikh Mkhitaryan is a key man in midfield at 36.

The Nou Camp and San Siro thrillers against Barcelona were a perfect clash of styles that delivered 210 minutes of the most spell-binding, watchable football, and it was the team with wing-backs that showed they had the tactical edge.

Inter might not be the only Champions League challengers playing that system next season. Xabi Alonso looks set to take over as Real Madrid manager, and the Spaniard has been wedded to wing-backs at Bayer Leverkusen. In a team often considered to lack a tactical identity, it would be fascinating to see Alonso drill Real into a three-man defence with flying wing-backs.

The system worked superbly for him in Germany, winning a remarkable Bundesliga title last season as well as winning the German cup and reaching the Europa League final. They are on course to finish second this time around.

What links Inter and Bayer Leverkusen is the quality of their wing-backs. Jeremie Frimpong is more of a winger than a wing-back and has played high up the