Arsenal had finished the previous season as runners-up in the Premier League, overhauled by Manchester United in the final ten weeks of the season. The club did, however, retain the FA Cup, with a 1–0 win against Southampton. Such was Arsenal's effective start to the 2002–03 campaign, manager Arsène Wenger suggested his team could remain the whole season undefeated in all competitions:
It's not impossible as A.C. Milan once did it but I can't see why it's so shocking to say it. Do you think Manchester United, Liverpool or Chelsea don't dream that as well? They're exactly the same. They just don't say it because they're scared to look ridiculous, but nobody is ridiculous in this job as we know anything can happen.[nb 1]
The team lost to Everton a month after Wenger's proclamation; teenager Wayne Rooney scored the match winner, which ended a run of 30 league games without defeat. By February 2003, Arsenal moved five points clear of Manchester United at the top of the league table, but injuries to key players, not least captain Patrick Vieira, had destabilised the team. Draws in April, coupled with a defeat to Leeds United at home, mathematically ended Arsenal's chances of retaining the title. Wenger refuted opinions from the media that their season was a failure and said:
Of course we want to win the league, but I think the most difficult thing for the club is to be consistent and we have been remarkably consistent. We lose the league to a team [Manchester United] who spends 50% more money every year – last year they bought a player for £30 million when they lost the championship. They will do the same next year and we [have] done miracles just to fight with them.
In the close season, Chelsea was sold to Russian billionaire Roman Abramovich for £140 million, the biggest takeover in British football history at the time.[nb 2] The takeover was welcomed by journalist Daniel King, who commented the club were better able to "break the Manchester United-Arsenal duopoly" in the league. Arsenal vice-chairman David Dein however was displeased, and quipped that Abramovich had "parked his Russian tanks on our lawn and is firing £50 notes at us", Abramovich was said to have placed a bid for Arsenal striker Thierry Henry, which was turned down at once.
Arsenal's transfer activity in the summer was relatively quiet, given the financial constraints that came with the club's new stadium project.[nb 4] The club were able to keep the core of its team, successfully negotiating new contracts for Vieira and winger Robert Pires. German goalkeeper Jens Lehmann was the only major addition to the first team; he replaced David Seaman who joined Manchester City. Ukrainian defender Oleh Luzhny ended his four-year association with the club by joining Wolverhampton Wanderers on a free transfer, while striker Graham Barrett moved to Coventry City. Striker Francis Jeffers, who found opportunities limited in the first team, joined his former club Everton on a season-long loan. Giovanni van Bronckhorst moved to Barcelona on a similar deal, with a view to a permanent transfer at the end of the season. Several young players were acquired from academies abroad, namely Gaël Clichy from Cannes and Johan Djourou, formerly of Étoile Carouge. In January 2004, Arsenal signed Spanish striker José Antonio Reyes from Sevilla and in April agreed a deal with Feyenoord for winger Robin van Persie.
Wenger at the start of the season prioritised regaining the league title: "I feel it is very important in our minds to do this and I know the hunger is strong to do it," and named Newcastle United and Liverpool, along with Manchester United and Chelsea, as Arsenal's main rivals for the Premier League. Former Arsenal midfielder Paul Merson asserted that his old club were favourites because they had the "best players … If they all remain fit week-in week-out then they will not be beaten." Glenn Moore of The Independent wrote of Arsenal's chances: "They will be thereabouts, but unless Wenger finally puts his faith in youth, and the likes of Jérémie Aliadière, Jermaine Pennant and Phillipe Senderos repay him, they may lack the depth to sustain a title campaign." Defender Sol Campbell however believed the squad was "strong enough for the league and FA Cup", but doubted their chances of winning the UEFA Champions League.
The club's home strip remained unchanged from the previous season; a red jersey with white sleeves, shorts and socks. The new away kit, a retro yellow jersey with a blue collar trim and shorts, was based on the Arsenal strip worn in the 1979 FA Cup Final.