It was, in many ways, one of the most extraordinary decisions of Arsène Wenger's managerial career but it also showed both his unstinting faith in youth and in Philippe Senderos in particular.
Selecting the 20-year-old Swiss defender ahead of a fit-again Sol Campbell in a showpiece match which Arsenal had to win to save their season was an act of boldness. And unflinching belief.
It caused ripples, not least in the Arsenal camp. Campbell, despite his apparently phlegmatic approach to life, could barely conceal his wounded pride. As he emerged from the dressing-room area at the Millennium Stadium, the man who has been the cornerstone of his side's defences, said simply, "I am fit and well", before heading for the team coach with a shrug.
Senderos was the next Arsenal player to appear. "We made the team plan yesterday and I was delighted to be playing," he said in that preternaturally mature way of his way of his. "There's healthy competition for places now. It's great to have Sol Campbell back alongside me in training because you learn so much from him."
In truth, the player who may have cause for greater concern at Senderos's burgeoning progress is his defensive partner on Saturday, Kolo Touré. It could be that he finds himself omitted, or competing with Lauren for the right-back position, come next season.
Wenger certainly intimated that Campbell's future was secure. "It was a very difficult decision," he said of leaving out the 30-year-old England defender, who has also seen his place in the national side taken by another, in that case John Terry, while he has struggled with injury. "I love Sol Campbell," Wenger added, "but I just felt that he had been out for 14 games. He played in two matches but I had a feeling that he wasn't completely ready for 90 minutes and that in the last 15 or 20 minutes he would've been a bit short.
"I must say that Senderos and Kolo worked very well. If you look at the record we have achieved recently, we don't concede goals. But Sol will be back in the team at the beginning of next season."
Arsenal's record with Senderos has been nothing short of remarkable, especially when it is considered how soft they had been in the centre of defence at times this season. Indeed, Wenger recently noted that up until Christmas only one team, Charlton Athletic, had lost more headers in their own penalty area than Arsenal. Set-pieces proved their undoing.
Senderos's emergence has changed that and is a powerful confirmation that Arsenal may have solved one of the problems that has undermined their progress, particularly in European competition. Of the last 16 matches he has played - 14 for Arsenal and two for Switzerland - just three goals have been conceded. Two of those came in Arsenal's last Premiership match of the season at Birmingham City - when he was paired with Campbell.
What has been even more promising for Arsenal is the way that Senderos has, game by game, visibly improved. The turning point undoubtedly came in the second leg of the Champions' League tie against Bayern Munich when he was often left isolated as Arsenal pushed forward. Suddenly he looked quicker, stronger, able to recover and more sure on the ball. At 6ft 3in he is also a powerful and astute reader of the game, who, it is hoped, can not only emulate Campbell but Tony Adams as well.
"Every game you play you take more confidence," was Senderos's own verdict. "For a young player playing week after week you grow as a person as well. It gives you confidence. I also had things going for me as the team has been doing very well." It helps that his best friend at Arsenal - and his house-mate - Cesc Fabregas has had such an outstanding season.
Senderos, who speaks Spanish, English, German and Italian as well as French, has already showed the right determination to succeed. After joining Arsenal in the summer of 2003 - when Wenger held off competition from Europe's top clubs, including Bayern, Real Madrid, both Milan clubs and Manchester United - Senderos suffered a back injury and then a broken bone in his foot which denied him almost a whole campaign.
Senderos, who is from Geneva, joined Arsenal from Servette after bursting to prominence as captain of the Swiss under-17 side which astonishingly won the European Championships in 2002 when they beat England along the way. The score that day was 3-0 and, for Senderos, there was the satisfaction of keeping Wayne Rooney's name off the scoresheet - a feat he, of course, repeated at the weekend.Reuse content