A manager can always spare a moment for a little extra worrying. In the build-up to the FA Cup semi-final with Manchester United that Arsenal were to lose, there was an aside from Arsene Wenger about the way in which Chelsea's wealth had changed the frame of reference in English football. When someone commented that it still takes time to build a team, the manager shot back that you can do it a lot faster with large sums of money.

He would rather not have been proved right quite so soon. A tight-knit Chelsea knocked out Wenger's unravelling Arsenal in the quarter-final of the Champions League at Highbury on Tuesday. The visitors developed a concerted power that could not be denied in the second half as they cleared a 1-0 deficit to win with Wayne Bridge's 87th-minute goal. The scorer, bought with the Roman Abramovich roubles last summer, could be taken as the epitome of the new, rapacious Chelsea but the reality is more subtle.

Of the starting line-up at Highbury, Mario Melchiot, John Terry, Jimmy Floyd Hasselbaink and Eidur Gudjohnsen were already at the club when Claudio Ranieri was appointed manager in September 2000. Had it not been for broken fingers, their number would have been expanded by the inclusion of Carlo Cudicini.

On top of that, Tuesday's line-up included William Gallas and Frank Lampard, who were signed during Ranieri's first year at Chelsea. In this taxing period he turned largely to the past for his initial team selection, with only Bridge, Scott Parker, Claude Makelele, Damien Duff and the anomalous free-transfer recruit Marco Ambrosio to represent the Abramovich era.

Hernan Crespo, Adrian Mutu, Joe Cole and Geremi, bought for a total of £46.2 million since the advent of the Russian billionaire, were named merely as substitutes. With the injuries to Glen Johnson and Juan Sebastian Veron, who together cost £21 million, Abramovich's investment was all but submerged. It would be pleasing to see this as a snub from a manager to an owner who is loth to confirm he will still have the job next season. That interpretation, however, would also be utterly wrong. It is really Abramovich's means that let Ranieri use long service as the theme of his team selections. At present, by comparison, a rival like Wenger must virtually send out everyone who is still healthy enough to run.

Having previously rotated midfielders and forwards in particular while making the most of an expansive squad, Ranieri can expect anyone he picks at this stage to have a healthy glow. Lampard is the sole freak among the players who cover the most ground. The England international, who is hardly ever sidelined, did droop in the FA Cup and Premiership defeats by Arsenal, but his slump seems only to have lasted for that seven-day period.

Others are feeling the advantage of the compulsory rests they resented. The vitality of the lithe and quick Gallas quelled Thierry Henry on Tuesday, although the forward had a hamstring strain that will rule him out of at least the Easter programme.

"We have a big squad and we are able to rotate players," said the Chelsea defender. "When you are playing so many matches at the top level, that is indispensable."

It is premature and even sycophantic to claim that Ranieri has timed his season perfectly. Chelsea can still go wrong in the Champions League and, while Arsenal need a maximum of 18 points from their remaining eight fixtures to be sure of the Premiership title, the actual target figure will probably be lower. The Stamford Bridge side, for example, are not guaranteed to keep on winning at venues such as St James' Park and Old Trafford.

Ranieri must wait to see if Arsenal's legs give out so that they weave across the track instead of charging straight for the finishing line. The 30-game undefeated run in this season's Premiership has started to look like the tough front-running of an athlete who knows that he does not have the pace for a sprint finish.

Wenger was concerned by a schedule of four matches in nine days that ends at Newcastle on Sunday but they started to wheeze when that sequence was barely begun. Although Patrick Vieira, Robert Pires and Freddie Ljungberg had been excused international duty, Arsenal were underpowered in the FA Cup semi-final last Saturday and conceded a goal before the interval from which they never suggested they could recover.

There was nothing abnormal for Arsenal in finding that they had to go into action again three days later. Indeed, one might have supposed that Wenger had been husbanding energy for the Champions League mission, where Henry was reinstated in the starting line-up. Though the side did play bullishly at the start, their energy level dropped sharply as soon as the second half was under way.

Perhaps Arsenal would have steadied themselves if Jens Lehmann had not made the mistake that let Lampard equalise but Wenger's team was not designed for scuffle and muddle. Now that Arsenal really do have cause to be weary, it has become essential for them somehow to scramble through against Liverpool at Highbury tomorrow.

It is not the most recent stretch of the programme that has sapped Arsenal. This has been a gradual, irresistible process. The home victories over Charlton and Bolton, in which they overwhelmed the opposition to build a 2-0 lead before conceding a goal to end the afternoon in a panic, no longer look like idiosyncrasy. By the time of Manchester United's 86th-minute equaliser in the Premiership 11 days ago there was no longer any doubt about the ineradicable vulnerability in the Arsenal side.

It is the price of its attractiveness, yet the constraints of what Wenger euphemistically terms a "compact squad" are exacerbating the problem. He has had one or two welcome surprises, such as the precocious expertise of the 18-year-old Gael Clichy, but he cannot engage in juggling of the line-up as United and Chelsea do. The Old Trafford side have created their own commercial strength and Abramovich has endowed Stamford Bridge with his fortune but Arsenal do not enjoy those means.

The strategy for bringing such funds into being rests on the construction of a new stadium, yet in the short term, while backers were being sought, that project only circumscribed Wenger even further.

The purse strings were slackened once investors were persuaded to support the Ashburton Grove plan and the manager was able to buy José Antonio Reyes during the transfer window in a deal that could eventually cost the club around £17 million. Wenger must be relieved he committed himself to signing the 20-year-old immediately. Although his former club Sevilla have claimed that they billed Arsenal for double the forward's real worth, Reyes does seem valuable. For someone who was supposed to have experienced a dreadful wrench in leaving his native Andalucia, he is remarkably at ease on a north London field.

With Henry hurt, it may take inspired moments from someone like Reyes to ease the passage to the Premiership title. For the rest, the weary side, whether they like it or not, will have to show they can scrap and scrape a way through. Arsenal should still become champions but they may not resemble their sleek selves while doing so.