The wing-back is the third generation of his family to be named Marcos Alonso and play professional football at the highest level. For his father that was at Barcelona and Atletico Madrid, but his grandfather, who was known as Marquitos during his playing days, spent eight years with tonight’s opponents Real Madrid.

In Marquitos’ time with the capital club he played at right-back in Los Blancos’ all-conquering side of the early European Cup era, alongside such greats of the game as Ferenc Puskas, Raymond Kopa, Francisco Gento and Alfredo Di Stefano – in whose honour the stadium which hosted our first leg is named.

‘My grandfather played for Real Madrid in the 1950s and 1960s when they won the European Cup five times in a row,’ recalled Alonso in an interview with the official Chelsea matchday programme.

‘He used to have all the replicas of the European Cups and a couple of league trophies. Sometimes I met his old team-mates from that great team but I didn’t even know who they were because I was a little boy!'

That must have been some mantelpiece display for Marquitos, as he lifted the European Cup for an unequalled five successive years, in addition to claiming five La Liga titles, the Spanish Cup and the Intercontinental Cup.

As if that wasn’t enough to guarantee Alonso’s grandfather a place in the Real Madrid history books, his goal to level the scores with 20 minutes left as they came from two down to beat Reims 4-3 in the first-ever European Cup final certainly did the trick.

If there was any doubt in the young Alonso’s mind of the esteemed regard his grandfather is held in at the club, it soon became clear when he began his own career in the Real Madrid youth system.

‘He was still alive when I first joined the academy there. He came to two or three games, I remember, in my first year. Everyone wanted a picture with my granddad instead of watching us play!

‘I used to feel very proud of that, of my grandfather being so popular there and so loved by the people.’

However, while his grandfather remains a Real Madrid legend, his father Marcos played on the other side of two major rivalries, with Atletico Madrid and Barcelona, making for an unusual mix of family legends both for and against Los Blancos.

‘I saw a lot of videos and photos of my dad and my grandfather from their playing careers. There is one of my grandfather when his Real Madrid team landed at the airport after they won the European Cup in Scotland, and he was coming down the steps from the plane wearing a kilt. He used to tell me and my cousin that story a lot.

‘For my dad, there is one at my house in Madrid with him scoring a header in the last minute of the cup final against Real Madrid. It was an amazing jump, an amazing goal, and something I think every Barcelona fan remembers today. That’s a very special photo.’