He stayed in Pamplona for four years but was too scared to run with the bulls, yet his idea of fun is to play with a boa constrictor. Carlos Cuéllar is man of many contrasts, so who better to symbolise the Rangers side that has crept up slowly and caught European football by surprise this season?

Just like the Spanish defender’s pet snake, Titan, Walter Smith’s team have proved adept at squeezing the life out of opponents en route to the Uefa Cup final. On Wednesday, Zenit St Petersburg will discover in Manchester what Fiorentina, Sporting Lisbon, Werder Bremen and Panathinaikos already know: that Rangers have no need of venom up front, when they can kill the game at the back.

Twelve shutouts in 18 European games this season, in the Champions League and Uefa Cup, illustrate the value of Smith’s £2.5 million signing from Osasuna last summer. Cuéllar slipped straight into the Ibrox back four as if he had been playing in Scottish football all his life, forming a mean central defensive partnership with David Weir that has just seen Cuéllar named Scottish Football Writers’ Player of the Year.

The man from Madrid had to leave Titan at home when he decided to join Rangers. That had more to do with immigration regulations on pets and livestock than a fear that even dangerous snakes might find Glasgow too tough to handle.

“It is very difficult to bring a snake to this country,” Cuéllar said yesterday. “So, he is still in Spain, where I also have an English bulldog.”

Cuéllar has resisted the temptation to replace his Dr Doolittle life in Spain with Scottish activities, such as golf. “I am very bad at that,” he laughed. “I like everything about life in Scotland. I go for a walk down to Starbucks and get a takeaway latte and I go into the city centre with friends.”

The defender’s four seasons with Osasuna gave him plenty of opportunity to become acquainted with Pamplona’s trademark livestock, but Cuéllar eschewed the chance to run with the bulls through the Basque city’s streets. “It’s too dangerous, too crazy,” he explained. “I prefer to watch that on television.” Had he joined in, it is a fair bet that Cuéllar would have shown everyone a clean pair of heels: this is the man who was a budding track star when he grew up in Madrid, before football claimed him.

“I did athletics at school and I was among the best 1,500 metres runners in the region,” he said. “I won lots of trophies but when I was 17, I changed because I liked football better. I had the possibility of becoming a professional athlete but I chose football. My dream has always been to be a footballer.”

Cuéllar began his career with the Spanish third division side, Calahorra, before moving up to the second tier and Numancia in 2001. Two fine seasons there caught the eye of Osasuna, and Cuéllar moved to the north-west of Spain to play for one of La Liga’s most modest, but durable, sides. He helped Osasuna to reach the semi-finals of the Uefa Cup last season, losing to the eventual winners, Seville, but he had already made an impact on Smith when Rangers were knocked out by Osasuna earlier in the competition.

There was an air of disbelief in Spanish football when Cuéllar announced that he was leaving the most glamorous league in the world to play in Scotland. “When you are already in the best league in the world and you go to another one, people told me I was crazy,” Cuéllar said. “They said, ‘Why move, why go to a lesser league?’ However, here I have the possibility to play in the Champions League or to win the title in Scotland. If Rangers win the Uefa Cup, it will prove I was right.

“At teams like Real Madrid or Barcelona, you play in European finals or win titles but when you play for one of the smaller sides in Spain, you do not even play in Europe that often. I took the chance to come here and I am glad. Going back to Spain is not something I dream about from day to day. I am here playing for Rangers and I am more interested in being in the Champions League and winning trophies like the Uefa Cup.”

Even in the handful of daily Spanish football newspapers, Scottish football merits barely a mention. However, since Cuéllar’s move to Ibrox, that Iberian interest has soared. “Everyone in Spain wants Rangers to win the Uefa Cup,” he said. “Every newspaper, radio station and television channel has called me up for an interview. Now they know much more about the Scottish game.”

Cuéllar admits that he has been moved by the level of support he has received from the Ibrox fans since his transfer but already the Uefa Cup run has heightened interest from clubs in England about his talent and Smith and Rangers could find it difficult to hang on to their Spanish defender if the sort of money that moved Alan Hutton to Tottenham Hotspur is used as bait.

“In Spain the fans were warm to me but nothing compared to Rangers,” he said. “I supported Real Madrid when I was a kid and went to some Champions League games in the Bernabéu Stadium, but once you become a player in Spain, it is your job and you cannot become attached because you will then play for other teams.”

Cuéllar may have picked up the plaudits and the awards, but he is quick to establish that he owes a debt to 37-year-old Weir for helping him to adjust to British football. “Not only is David a great player but he is a good person off the pitch,” he said. “We have a very good relationship on and off the pitch and we operate well together. I hope he signs another contract. He can play for another two or three years. It’s easy for him.”