No standing still, no going back, and no retiring

What now for the champions: Ferguson has learnt his lesson that quality must be built on

Time waits for no manager, not even one as distinguished as Sir Alex Ferguson, and rivals desperate to deprive him of either a ninth Premiership success in 12 seasons or a second European Cup should not be fooled into confusing the "light, relaxed week'' which Manchester United have enjoyed with any suggestion of resting on laurels since securing the championship last Sunday.

Time waits for no manager, not even one as distinguished as Sir Alex Ferguson, and rivals desperate to deprive him of either a ninth Premiership success in 12 seasons or a second European Cup should not be fooled into confusing the "light, relaxed week'' which Manchester United have enjoyed with any suggestion of resting on laurels since securing the championship last Sunday.

There are enough laurels right now to start a garden centre and the wealth of experience gained in winning them – and, crucially, losing others – is one of Ferguson's greatest strengths.

It might have been lost to United had his family not famously talked him out of the decision to take what has now been confirmed as premature retirement. Instead the lessons of the club's history since Ron Atkinson was replaced in the autumn of 1986 (with United 19th in the table) have been stored in the hard disk of a brain renowned for retaining sufficient data to have contributed 250,000 words of long-hand to his autobiography.

Of all the lessons learnt in those unceasingly eventful 17 years, the most profound is that standing still is not an option. Many of the squad may still be improving – Ruud van Nistelrooy, alarming for opposing defenders, among them – but others have peaked and must be supplemented, if not actually replaced, over the next few months. On the other hand, the full-scale cull that Ferguson threatened after ghastly defeat away to Manchester City in November ("We've built three teams here. The next challenge may be to build the next one'') need not be as drastic, given the players' subsequent response.

Whatever the state of the market, no club, with the possible exception of Real Madrid, is in a better position to exploit it than United; certainly not Arsenal, whose inadequate defensive resources cost them any hope of carrying this season's championship chase to a thrilling climax this afternoon. Ferguson, being Ferguson, could not quite resist a little dig in the direction of north London yesterday: "Arsenal have got more problems than you think. They've got a bigger debt than you think."

While Arsène Wenger, burdened by his club's commitment to a new stadium that might be named The Albatross, struggles to do what he can with a £10m transfer budget this summer, United's manager expects to have a freer hand.

Naturally, he will not show it but was prepared to confide: "I've got my ideas. What we have to do here is always try to improve ourselves. If you stand still in this game, you go back, and we don't like to go back. If you miss the bus, you're behind and we want to move forward and to create a more competitive element in the club.''

That was a lesson painfully learnt after winning the Double nine years ago with the team of Paul Ince, Andrei Kanchelskis and Eric Cantona, then suffering a blank season immediately afterwards: "We should have done that in '94 and didn't. So I want to do that this year. That was a lesson, without question.'' It led to a poor Champions' League campaign, which under the new format next season would be a huge and expensive disappointment after reaching the knock-out stage for seven successive years.

Where then might the squad be strengthened? In goal for certain with a replacement for Fabien Barthez and, many would instinctively say, immediately in front of him. Oddly, however, there is a strong statistical argument for United to claim, "It was the defence wot won it". Once again the Premiership title went not to the team scoring most goals (Arsenal this season, United last time) but the one conceding fewest.

For all Van Nistelrooy's extraordinary exploits, improvement at the back was of immense significance to a side against whom only Manchester City, Middlesbrough and Newcastle managed to score three times. "You can see the marked difference in our defensive performance this season,'' Ferguson said. "Last year was an absolute holocaust of individual errors. This season that's been mainly eradicated. And the age [of the defenders] is good. You're thinking maybe they could have five, six, seven years together. And they will improve. Defenders and goalkeepers are not the finished article until they are 28 or 29.''

Laurent Blanc, oft criticised, will be leaving with the unusually sentimental gesture of a place in this afternoon's squad at Everton and this testimonial from the manager: "He's been brilliant, fantastic. It depends what you want out of a centre-half, of course. If you want one that sprints up to the halfway line and plays people offside all the time, then no. He knew his strengths. I wish we'd got him five years ago. Before the game against Charlton last week he was in the corner with big Rio just giving him a few things and Rio's like that, taking it all in, you know.''

Roy Keane could at some stage be drafted into the back-line to help bring on Ferdinand, Wes Brown and the versatile John O'Shea. In the meantime there was heartening evidence in a masterly performance against Charlton that Keane can still present a formidable barrier in front of the defence. The look of the midfield might be determined by how seriously the Milan clubs want either David Beckham or Ryan Giggs; either way extra goals from a regular new partner for Van Nistelrooy would be a worthwhile investment.

The English season is a long and winding road, and yet it is almost bizarre to recall that after six matches United had made their worst start to any Premiership campaign, scoring fewer goals than for 30 years, and Ferguson was saying of his star striker, who had one penalty to his name: "Ruud's lost a little bit of confidence." The Dutchman found it pretty quickly, and with only a stutter or two to come – at Maine Road, then Blackburn and Middlesbrough over Christmas – United were on their way. It remained only for Ferguson, echoing Keane, to ask a pertinent question or two about his players' hunger for more success: "You have to ask that because they're all wealthy young men and they've won everything you can win and I don't think it was impertinent to ask the question. The response was fabulous."

More impertinent would have been for any of the young millionaires to ask the same thing of a manager who has now won 21 trophies for the club. The answer might have surprised them: "Winning that first League [in 1993], I could have gone to heaven then. All the rest is bonus time. But time has given me the experience and the understanding of this club and what it needs."

More bad news, though, for those potential rivals: Ferguson has two years left on his existing contract – emphasis on the word existing – and no intention whatever of making any further statement about retirement. The flame still burns, flaring all the more brightly when he considers the club's future; recently he journeyed to Charlton and Middlesbrough to watch the successful pursuit of the FA Youth Cup, a trophy dear to United's heart since the teenaged Busby Babes won the competition's first five finals in the Fifties. The schoolboy level, he revealed, is also very good. "What's that, Alex, Under-15s?" "No, Under-9s and Under-10s."

Time waits for no one, but potential Manchester United managers should not bother typing a cv quite yet.

Missing pieces in the European jigsaw

Goalkeeper: No 1 priority
Fabien Barthez, dropped after the Champions' League quarter-final second leg against Real Madrid, is on the way out. The Spaniard Ricardo has proved too erratic, conceding goals, penalties and yellow cards in equal measure, which helps Roy Carroll by default. Southampton's Antti Niemi, Paul Robinson of Leeds and the Turkish international Rustu Recber are admired and would all be an improvement. Recber, out of contract with Fenerbahce, comes cheapest.

Case for the defence
With Laurent Blanc and David May (remember him?) leaving, there is room for a new centre-back like Auxerre's Philippe Mexes; European experience is essential. Rio Ferdinand, Wes Brown and John O'Shea are slowly gaining it, though mistakes were inevitably made in the past campaign. The last two, like Gary Neville and Mikaël Silvestre, can play at full-back or in the middle, and their manager, Sir Alex Ferguson (pictured), must decide on his best central pairing.

The middle men
The club's whole transfer strategy may well revolve around the size of bids that come in for David Beckham, Ryan Giggs or Juan Sebastian Veron. Giggs, 18 months older than the others, could sensibly be replaced by Damien Duff of Blackburn. Ferguson's stubborn faith in Veron will make him reluctant to sell the Argentinian, and Beckham's release could only be justified for silly money. As Roy Keane's powers wane – could he move into the back four? – a new holding player like Real's Claude Makelele will be needed.

A front for Ruud
If anything stops United's manager sleeping next season, it will be the thought of an injury to his irresistible striker Ruud van Nistelrooy. Signing Jermain Defoe (much easier if West Ham are relegated today) would guarantee that goals continued to flow in that event, as well as offering the Dutchman the perfect partner that Ole Gunnar Solskjaer did not quite prove to be. Ronaldinho from Paris Saint-Germain would be an even more exciting and no less costly option.