Paying homage to sporting heroes has long been a serious business in North America, where every team has a Hall of Fame to honour players who have left an indelible mark.

These history-makers took their clubs to fresh heights, and in exchange their squad numbers have been retired from service. It is a fitting tribute not bestowed lightly, but one fully deserved by talents such as former NBA star Michael Jordan and NHL legend Wayne Gretzky. Never again will a Chicago Bulls player take to the court with 23 on his back, and never again will the Edmonton Oilers hand out a jersey emblazoned with the number 99. 

In recent years, football has followed suit. This was impossible back in the days when teams wore shirts numbered from one to 11, but, since squad numbers were attributed to every player at the start of the season in the 1990s, the tradition has taken hold. With the practice growing, FIFA.com takes a look at some of the numbers that have been preserved for posterity.

Loyalty to the colours has always been a sure-fire way to acquire hero status, and in Italy several stalwarts have seen their loyalty rewarded with the ultimate tribute. Emblematic defender Franco Baresi is one of those, having formed a career-long association with  AC Milan , where he spent 20 memorable years. Upon his retirement in 1997, the Rossoneri showed their appreciation by withdrawing Baresi's number six shirt from circulation.

They will be performing a similar ceremony in a few months' time as well, when Baresi's successor as captain finally calls time on his playing days.  Paolo Maldini  has won every title under the sun during his time with the Lombardy giants and, possibly more than any other player, has come to symbolise AC Milan. "Paolo represents the history of the club," declared vice-President Adriano Galliani in January 2005. "When he finishes his career, we will retire his shirt." Unsurprisingly, the man himself admits to being touched by the gesture. "I'm really very happy and secretly I was hoping for it," he said. "The club have always been very good and respectful towards me." Having announced he will retire at the end of the current campaign, anyone hoping to see Maldini's iconic number three shirt should hurry to the San Siro fast.

Across the city at rivals Inter,  Giacinto Facchetti  is the only player to have been accorded the same honour. Another number three, the gifted full-back sadly passed away on 9 September last year, but not before making an enormous impact with both the Nerazzuri and the Italian national side. He graced Inter's colours 634 times between 1961 and 1978, winning four scudetti and two European Champion Clubs' Cups, while with the Azzurri he lifted the continental trophy in 1968 and finished runner-up at the 1970 FIFA World Cup Mexico™. "Giacinto was an even greater man than he was a player," noted no less an authority than Gianni Rivera, his international team-mate and another legend of the Italian game. "He consecrated his entire life to football. He was a good man, full of integrity." 

Other figures full of significance for Serie A fans include the number six made famous by Brazil's Aldair at AS Roma, and the number 11 forever linked to Cagliari ace Gigi Riva. 

Perfect ten
In contrast,  Roberto Baggio  spent just four years at Brescia - his last as a player - but in that short space of time the 1993 FIFA World Player of the Year and Ballon d'Or winner altered the history of the club.

Before he arrived in town, the Lombardy outfit had never been able to sustain themselves in the top flight, yet with the former Juventino working his magic they kept themselves in Serie A and even tasted UEFA Cup action in 2001/02. Once the Divino Codino finally hung up his boots in 2004, with 452 matches and 205 goals to his name, Brescia expressed their gratitude by withdrawing his number ten shirt. And as if to underline his importance, they were relegated the very next season.

A few years previously and further south, another legendary number ten was lighting up the Italian championship. If Napoli now count as one of the biggest names in Italy, they owe it practically all to one man: Diego Armando Maradona. When the Argentinian first showed up at the Sao Paolo stadium in 1984, the club trophy cabinet contained nothing more than two national cups. That was all about to change, though, and seven years later they had been crowned champions twice, added a third cup trophy, won the UEFA Cup and gained international renown. To this day, the former world champion is a sacred figure for Napoli fans, and the club have wisely decided that nobody should have to suffer the inevitable comparison by slipping on the mythic number ten shirt he made his own.

Likewise, the Argentinian Football Association no longer attributes Maradona's number to players at senior or youth level, except during official FIFA competition, when all 23 squad members must be numbered in order. It is a policy that has met with widespread approval, with fellow idol Mario Kempes one of few dissenting voices. "Ten is the number worn by the best players in the world and I think Argentina will have another player like Diego one day," he said. "For me, an Argentina side without a number ten is just shocking." As it happens, El Matador could well have his way. Indeed, Maradona himself has made it known he would appreciate watching youngster  Lionel Messi  take the field wearing the revered figure on his Albiceleste strip. 

Posthumous honours and 12th men
While retiring a shirt number is undoubtedly a sign of respect, some clubs would have gladly preferred not to go down that road. Sadly, a large number have been withdrawn in homage to players who passed away far too young.

Thus, following  Marc-Vivien Foe's tragic death  after the FIFA Confederations Cup semi-final between Cameroon and Colombia in 2003, Lens and Lyon both retired the number 17, while Manchester City did the same with the number 23. In a similar vein, Chievo Verona and Brescia no longer hand out the numbers 30 and 13 respectively, in honour of Congolese player Jason Mayle and Italian defender Vittorio Mero.

At Benfica, meanwhile, the number 29 will never be worn again, as a tribute to  Miklos Feher , who suffered a heart attack during a match against Vittoria Guimaraes on 25 January 2004. The Hungarian striker still occupies a special place in the hearts of the club's fans, and his story has touched supporters further afield as well.

In fact, almost three years after his death in November 2006,  Celtic fans  at the Stadium of Light for a Champions League encounter held aloft a banner inscribed with the number 29 and the message 'Feher: Nunca caminharas sozinho' ('You'll never walk alone'). Portuguese international forward Nuno Gomes was one of many to be touched. "It was a unique moment and a magnificent gesture," he said. "What a great example of fair play. We think about our friend Miki every day. He's always with us."

Like those Celtic supporters that day, football crowds all across the world are recognised as being an integral part of the action whenever two teams lock horns. Therefore, it is no surprise that some clubs have gone the extra mile and given their loyal following a squad number. Usually, 12 is the chosen digit, as is the case for Fenerbahce, Lens, Feyenoord, Portsmouth, Norwich City, Malmo and  Zenit St Petersburg . Greek side Panathinaikos buck the trend, however. Despite recognising their supporters as the '12th man' like everybody else, they retired the number 13 as a way of thanking the group of ultras who streamed through Gate 13 at their old Apostolos Nikolaidis stadium.

Whether heroic or tragic, the fates of some of football's most enduring protagonists have lent their shirt number lasting resonance. Often, those numbers have become so iconic they add huge pressure to players following in the footsteps of a departed great.

In that sense, France can count themselves fortunate that  Zinedine Zidane  finally broke the spell cast on the number ten jersey by Michel Platini, but since his retirement the conundrum has resurfaced. Manchester United supporters would be forgiven for thinking their number seven shirt is blessed, on the other hand, having seen it worn with distinction by George Best, Bryan Robson, Eric Cantona, David Beckham and  Cristiano Ronaldo  down the years.

In both cases, their successors will be painfully aware they are not there simply to make up the numbers.