Two metres tall, head to toe, with the wingspan of an albatross and a neck that seems to reach up into the clouds, Thibaut Courtois was always going to leave a very distinct and sizeable gap when he departed Chelsea in the summer of 2018. You can measure it in currency as well as in metres. The London club spent in excess of €100 million replacing the excellent, elastic Belgian goalkeeper. Most of that went on making Kepa Arrizabalaga the most expensive keeper in football, at some €80m. But Kepa will be watching Tuesday’s first leg of the Champions League semi-final against Courtois’ Real Madrid from the substitutes bench, his Chelsea career having hit some uncomfortable bumps in his second season at the club. He is now firmly assigned as deputy to Eduoard Mendy, bought in last summer for just over €20m, and already the proud co-owner of a defensive record Courtois can relate to. Chelsea have kept 16 clean sheets since Thomas Tuchel arrived as their new manager 21 matches ago, Mendy the last line of defence for most of those, and, apart from a bizarre afternoon – <a href="https://www.thenationalnews.com/sport/football/chelsea-v-west-bromwich-albion-player-ratings-thiago-silva-2-marcos-alonso-4-matheus-pereira-a-perfect-10-1.1196282">a 5-2 defeat by West Bromwich Albion</a> – the confident commander of a successfully reshaped defence. Three at the back, with wing-backs, is the default under Tuchel; under his predecessor, Frank Lampard, it was an option. In the lead-up to Chelsea’s first European Cup semi-final for seven years, the Tuchel back-three is being widely referred to as 'The Wall', Chelsea’s secure base as they chase a top-four finish in the Premier League and two major trophies, the FA and European Cups. “They are a very complete side,” said the Madrid central defender Raphael Varane on Monday, “and we will need to be flexible in the way we take them on. They have a really solid block at the back and they come at you fast.” “We need the very best version of ourselves to do damage to this Chelsea,” added Real manager Zinedine Zidane. Zidane will not have his preferred XI at his disposal. Eden Hazard – like Courtois a distinguished former Chelsea player – is not thought sufficiently match-fit to start, although his 15 minutes from the bench in Saturday’s 0-0 draw with Real Betis was one of his more encouraging comebacks of his injury-troubled time in Spain. Hazard should be in the match day squad. Captain Sergio Ramos is still in recovery from a muscle problem and left-back Ferland Mendy ruled out with injury. That’s two absentees from the first-choice back four. But Courtois is used to giving orders to different combinations of defenders. Madrid were missing Varane, Ramos and right back Dani Carvajal for the quarter-final win over Liverpool, and they have fielded mix-and-match defences through a run of six La Liga matches in which only one goal – <a href="https://www.thenationalnews.com/sport/football/real-madrid-v-barcelona-player-ratings-casemiro-loses-his-head-as-benzema-keeps-his-mingueza-man-of-the-match-as-messi-struggles-1.1201036">in the victory over Barcelona</a> – was conceded. Varane praises Madrid’s tall goalkeeper for his consistency in those circumstances. “He’s having a really good season,” said Varane of Courtois. “We have had to adapt to lots of changes in the team, but that’s a challenge I enjoy for my game, and defending well is always a question of the whole side defending well.” Madrid should have all three members of their trusted midfield shield available, Toni Kroos passed fit to line-up with Luka Modric and Casemiro. There was a nod of approval from Varane for Gabriel Militao, the Brazil defender who has deputised impressively for the absent Ramos. Militao has had to bide his time in the two years since Madrid recruited him from Porto for around €50m. “When you haven’t built up your rhythm it is hard coming into a team,” said Varane, “but we all knew from training with him the quality ‘Mili’ has, and he has a great attitude to work, and is always positive. We talk a lot on the pitch.” “He’s shown a lot of patience,” echoed Zidane, “and now he’s bringing a lot to our team. We’re all very happy with him.” Madrid approach their ninth Champions League semi-final of the last 11 seasons with Zidane refusing to comment on whether the drama over the proposed, and rapidly collapsing, idea of a breakaway European Super League – driven above all by the Madrid president Florentino Perez – had been disruptive for the dressing-room. The club may yet face sanctions from Uefa for having signed up to the project. “We are here to play a match, that’s the focus,” Zidane insisted in answer to questions on the Super League fallout.