No competition makes Cristiano Ronaldo come more alive than the Champions League.

And no team makes Ronaldo come more alive than Atletico Madrid.

So Diego Simeone and his players could be forgiven for feeling a certain amount of trepidation when Ronaldo arrives at the Wanda Metropolitano for Wednesday’s last-16 match between Atletico and Manchester United, despite the Portugal superstar — at 37 — not being quite the force of nature who caused the Spanish club so much pain in the Champions League over the past decade.

From 2014-19, when Ronaldo played for Real Madrid and then Juventus, he was part of teams that ended Atletico’s Champions League title ambitions in five of the six seasons. In the other season, Atletico didn’t make it to the knockout stage.

Ronaldo scored hat tricks for Real (in 2017) and Juventus (in 2019) against Atletico, and converted the clinching penalty in the shootout between the Madrid rivals in the 2016 final. Don’t forget, either, his muscle-flexing celebrations after his late penalty in extra time of the 2014 final between the teams that killed off Atletico.

Up until 2020, Simeone had only ever lost in the Champions League knockout stage to a team containing Ronaldo.

Oh, and for good measure, Ronaldo grabbed hat tricks against Atletico in the Spanish league in 2012 and 2016.

Wednesday’s game will be the first time Ronaldo and Atletico have crossed paths since November 2019. Since then, Ronaldo has pulled clear as the all-time leading scorer in Champions League history with 140 — 15 more than Lionel Messi and 58 more than the next player on the list, Robert Lewandowski.

And the fire burns inside Ronaldo as much as ever on Champions League nights.

Goals haven’t been so easy to come by since his return to United last year, with the team enduring a turbulent season that has featured a change of manager. Indeed, Ronaldo has just one goal in his last eight games in all competitions, making it one of his leanest spells since becoming a scoring machine in the latter part of his first spell at United from 2003-09.

Yet, Ronaldo scored in all five group games in which he played, including late winners against Villarreal and Atalanta at home and a stoppage-time equalizer at Atalanta. He lives for the big stage and the big moments, so he’ll relish a return to Madrid to play his favorite opponent.

An injury to fellow striker Edinson Cavani and the continued absence of Mason Greenwood has meant Ronaldo has started in each of United’s last three games, playing 90 minutes in two of them and 85 in the other. United has been careful to avoid over-playing Ronaldo this season, leaving him out of some games.

Starting four games in 12 days isn’t ideal for Ronaldo, even if his sharpness and fitness levels are staggering for a player his age.

Don’t expect him to be out of the team on Wednesday, though.