The key clashes as Tottenham face AC Milan in the Champions League.

The Champions League returns on Tuesday, with AC Milan and Tottenham facing each other in the first leg of their last-16 tie.

An entertaining encounter is expected at the San Siro, and Sportsmail's Daniel Matthews outlines the key clashes that could decide the outcome of the game.

Cristian Romero v Rafael Leao

Tottenham’s injury list will force Antonio Conte into a midfield reshuffle but Cristian Romero will return to provide stability on the right side of their back three.

That should pit the World Cup winner against Rafael Leao, one of the most dangerous young forwards in European football. The 23-year-old, already a Portugal international, is a rangy, fearless runner with an eye for goal and magic in both feet.

It promises to be a severe test for Romero, who never shirks a physical battle but has an unfortunate habit of being sucked into challenges. He is never far away from a card

Harry Kane v Simon Kjaer

This would be a fourth meeting between Tottenham’s all-time highest goalscorer and the veteran at the heart of AC Milan’s back four, but the first at club level. Kane and Kjaer last met in the semi-finals of Euro 2020, when England overcame Denmark after extra time at Wembley.

Kane’s movement could cause problems for Kjaer, who turns 34 next month and has struggled both with injury and form. His place is under threat from Malick Thiaw, 21, but Kjaer still offers vital defensive leadership and if he can stifle Kane’s influence, Milan will go a long way to shackling Spurs’ attacking threat.

Oliver Skipp  v Sandro Tonali

Injuries and suspension have ravaged Conte’s midfield options. Yves Bissouma (ankle), Rodrigo Bentancur (knee) and Pierre-Emile Hojbjerg (suspension) are missing, meaning Oliver Skipp is likely to anchor the Spurs side alongside Pape Matar Sarr.

Skipp has made just five starts in the past 12 months following his own nagging problems with injury and illness. Milan have midfield issues of their own but Sandro Tonali is a regular in Stefano Pioli’s side. A classy player with a great touch, he offers a threat from dead-ball situations.