Born in Mitcham, Surrey, Stepney had unsuccessful trials with Fulham and joined Tooting & Mitcham United. From there, he was spotted by Millwall, who signed him as an amateur in 1963, but quickly realised his potential and made him a professional within two
months of his arrival. Stepney was ever-present for almost three seasons, making 158 appearances, only missing the last game of the 1965–66 season. During this period, he earned three England under-23 caps.
In May 1966, Stepney joined Chelsea for £50,000. Manager Tommy Docherty initially intended to play Stepney and fellow goalkeeper Peter Bonetti in alternate weeks, but just three months later Stepney was sold to Manchester United for a record fee of £55,000, having made just one appearance for the club. With Harry Gregg's career virtually ended by injury, the Manchester United manager, Matt Busby, opted for Stepney after deciding that neither Pat Dunne nor the injury-prone David Gaskell was up to the job. Stepney made his debut for United later the same year against Manchester City at Old Trafford, and he kept a clean sheet as United won 1–0 through a first-half goal from Denis Law.
League and European exploits
With Stepney in goal, Manchester United won the First Division title in 1967, earning them entry into the European Cup the following season, a competition that no English club had yet won. Stepney featured throughout United's progress to the final at Wembley Stadium, during which he made a memorable close-range save from Benfica striker Eusébio in the closing stages with the score at 1–1. Eusébio was so astonished at Stepney's save that he stopped to applaud the keeper as Stepney threw the ball back into play. United eventually won 4–1 after extra time.
At the start of that season, Stepney had conceded a goal to his opposite number at Tottenham Hotspur, Pat Jennings, in the 1967 FA Charity Shield at Old Trafford. With Tottenham leading 1–0, Jennings punted the ball upfield from the Stretford End; the ball bounced over the stranded Stepney into the net. The game ended 3–3 with United's goals coming from Bobby Charlton (2), and Denis Law.
Although a highly talented keeper, Stepney was a distance down the pecking order when it came to the England team. Gordon Banks was the undisputed number one, with Peter Bonetti of Chelsea, Gordon West of Everton and the more experienced Sheffield Wednesday goalkeeper Ron Springett all in Stepney's way. When England qualified for the final stages of the 1968 European Championships, coach Alf Ramsey selected Stepney and West as the two back-up keepers to Banks and, in what turned into a momentous week for Stepney, he made his England debut in a friendly win over Sweden in May 1968, seven days before the European Cup final. England won 3–1.
Ramsey kept Stepney in his thoughts in his preparations for England's defence of the FIFA World Cup in 1970, for which England did not have to qualify having won the previous tournament, but did not give him another cap as the likes of Bonetti and West added to their meagre tallies of appearances. However, when the preliminary squad of 27 was announced, Stepney was in, along with Banks, Bonetti and uncapped rookie Peter Shilton, with no sign of West. When the final 22 who would travel to Mexico was confirmed, Shilton was the goalkeeper sent home.
Nevertheless, Stepney was clearly the third-choice goalkeeper in the squad and the chances of his appearing on the pitch in Mexico were small. When Banks went down with food poisoning prior to the quarter-final with West Germany, it was the slightly more experienced Bonetti – who had six caps to Stepney's one – to whom Ramsey turned, although Stepney did make it onto the substitutes' bench. England squandered a two-goal lead to lose 3–2 and it was Stepney who told the groggy, ill Banks the scoreline in his hotel room by holding up three fingers on one hand and two on the other.
United's fall and rise
Stepney was occasionally recalled by Ramsey but would ultimately not add to his solitary England cap, with Shilton emerging as the new deputy and ultimate long-term replacement. He continued to play in goal for Manchester United in a period of significant underachievement for the club, which culminated in their relegation to the Second Division in 1974, a season which saw Stepney, unusually for a goalkeeper, score two goals from penalties thus making him the (joint) leading scorer at Christmas. For half a season he was replaced by Jimmy Rimmer. By now, with Stepney's former Chelsea manager Tommy Docherty in charge, they bounced back as Division Two champions the following season (1974–75). During this time, Stepney suffered a freak injury when he dislocated his jaw barking instructions at his disorganised defence.
The next two seasons saw Stepney as the wise head behind a new, youthful team collated by Docherty courtesy of some astute purchases and a prolific youth set-up. During this period, Stepney had to compete with Paddy Roche for a regular starting position. Stepney was the only player with any Wembley experience at club level at all when United reached the 1976 FA Cup Final and the nerves of the youngsters got the better of them as Southampton, a division below United but containing some experienced heads of Stepney's generation, won 1–0. Stepney had no chance with the goal from Bobby Stokes, a late, low, crossfield shot which United claimed fruitlessly was from an offside position.
United reached the Cup Final again in 1977 and this time were successful. Stepney got a hand to a bullet shot on the turn from Jimmy Case but couldn't stop it entering the net and levelling the match after Stuart Pearson had scored for United. Jimmy Greenhoff quickly restored United's lead and Stepney made some good saves in the closing stages as Liverpool, chasing an unprecedented 'treble' of trophies (having already won the league title, and just days later going on to win the European Cup), piled on the pressure.
Stepney was the only player in the 1977 FA Cup winning team remaining from the European Cup winning side of nine years earlier. Stepney was also the last remaining player to play for the club under manager Sir Matt Busby.
End of an era
The following year, Stepney was again not an automatic choice, playing fewer than half of United's games in the League. He played the last of his 546 games for Manchester United in April 1978, prior to leaving for Dallas Tornado in the North American Soccer League in the United States, where he remained until he retired from professional football in 1980.
He kept 175 clean sheets, made a club record 92 consecutive appearances (later broken by Steve Coppell) and, with those two goals, remains United's top scoring goalkeeper. Aside from Peter Schmeichel (who scored in a UEFA Cup game in the 1995–96 season), no other Manchester United goalkeeper has scored in a competitive game for the club in the post Second World War years.
Towards the end of his career, he turned out for non-league side Altrincham in the early 1980s, when they were competing in the Alliance Premier League (which became the Football Conference in 1986). He helped them win the Alliance Premier League title in 1980–81 (they had won it the 1979–80 season as well), but they did not win promotion to the Football League as the re-election system was still in place and the majority of the league's members voting against them joining the Football League, ending Stepney's hopes of a professional comeback.
Stepney became a coach specialising in goalkeeping after he stopped playing, including a spell at Manchester City in 2000–01. He also works as an after-dinner speaker and currently hosts The Legends Football Phone in on 105.4 Century Radio in Manchester, replacing Mickey Thomas – another former Manchester United player.
Style of play
Stepney was never a flashy performer and perhaps his most impressive quality was his positioning, though he could also demonstrate agility when required. Alex was a good 'talker' who expected – and usually got – the final say in his penalty box, and was a constructive user of the ball who would never 'hoof it' upfield when he could throw to a well-placed colleague