Ronaldinho sets the beat for Barcelona's high-speed dancing

The Spanish league is stronger this season than last, and after six games Barcelona look some way short of their best form. Yet they are top of the table, first in goals scored and unbeaten. Even with the long-term loss through injury of Samuel Eto'o, their best bet for European Footballer of the Year out of the eight players they have in the final 50, the reigning Spanish and European champions continue on the up and up.

Their victory on Sunday night, 3-1 at home against the Uefa Cup holders, Seville, was their best of the season - against a team that are also improving, and that look like a very good bet to end up in the Spanish top four. Even more ominously, Ronaldinho, who had not yet caught fire, did. He scored twice, one of them a free-kick from the edge of the penalty area, and imposed his stamp on the game with aplomb and samba class.

After the game he said there was still "a long way to go" before he was 100 per cent. The sense, though, is that he was exaggerating just a bit; that he is timing his return to form to coincide with a big week in which, having played Seville, Barcelona take on Chelsea at Stamford Bridge tonight and then, on Sunday, Real Madrid at the Bernabeu.

Under the cool and collected Frank Rijkaard (there is no one cooler or more collected in the game), Barcelona spent the summer fine-tuning what was already the slickest machine in world football. Since defeating Arsenal in the Champions' League final in May, Barça have made three judicious new acquisitions and recovered two excellent players who missed much of last season through injury. They picked up Lilian Thuram and Gianluca Zambrotta in the Juventus summer sales and Eidur Gudjohnsen from Chelsea. Leo Messi, the mesmerically nippy Argentine forward, is back and so is Xavi, Barcelona's Paul Scholes - the intelligent, talented, tidy rival to Liverpool's Alonso for the role of midfield orchestrator in the Spanish national team.

All three new boys have slotted in soundlessly. Zambrotta, so impressed by his new club that yesterday he described Barcelona as "the best team in Europe and in the world", remains as redoubtable and polished a full-back as he was in Italy. Thuram might be approaching elder statesman status at 34, but he appears more than content to play second fiddle in central defence to the Barça captain, Carles Puyol, and the excellent Mexican Rafa Marquez. Thuram has played in half Barça's games so far, and - having looked as comfortably commanding as ever - will probably play many more.

As for Gudjohnsen, who arrived from Chelsea in the summer, he has taken immediately to the club and they to him. The fact that he scored a screamer in his first league game - lobbing a ball on the volley over a defender's head with his left foot, and then smashing it home with his right - undoubtedly helped. His fighting attitude, his muscularity, his angelic looks have charmed the Nou Camp faithful, and he has taken over the slot left by Henrik Larsson, who has gone into semi-retirement in Sweden, so seemingly effortlessly that Barça fans continually muddle one name with the other.

If there is a doubt at Barça, though, it does concern the Icelander, who has suddenly been obliged to fill the very large shoes indeed of Eto'o, out till February, at least, with a knee ligament injury. Eto'o is the most lethal goalscorer in Spain and - together with Thierry Henry - in the world right now. Gudjohnsen is strong and skilful enough, but he lacks the Cameroonian's unpredictable electricity.

If anyone is to surprise Barcelona in Spain or in Europe this season it will have to be over the next four months, before Eto'o's scheduled return. There again, what Barça do have going for them, perhaps more than any other team anywhere at the moment, is a multiplicity of players who can and do score goals. As third-choice striker, Argentina's Javier Saviola is an impressive option. Saviola is different from Gudjohnsen in practically every respect. Small, frail and furtive, he is nevertheless a formidable goalscorer. He has yet to play alongside Gudjohnsen but the two could form an intriguingly complimentary duo.

Yet it is from neither of these two that Barcelona's main threats come. Chelsea, whom Barça regard with as much respect as Chelsea regard them, know full well that Ronaldinho is the man to stop; the best player in the world. And then there is Messi, who is showing every sign, at 19, of confirming the suspicion that he is going to be one of the great players of the next decade. His goal against Seville on Sunday was one that most top-class forwards would be happy to score once in their lives. With Messi, you know he will repeat it 20 times before he retires. On the edge of the penalty area with four Seville defenders - who are no marshmallows - in front of him, what did he do? In the blink of an eyelid he was somehow on the other side of them, with only the goalkeeper to beat, which he did.

Other Barcelona goalscorers: Ludovic Giuly, Messi's almost-as-quick understudy; Deco and Xavi, who both have terrific long-range shots; Marquez, a peril at corners, who can also take free-kicks from the edge of the penalty area, should Ronaldinho want to take a rest; and Andres Iniesta.

Iniesta is quite possibly the most underrated football talent in the world today. Outside Barcelona, at any rate. For at the Nou Camp they value him as much as any other player. Not only does he score, typically with late runs into the box, he is one of those complete midfielders of whom managers dream. Strong and brave and tireless in recovering the ball, he runs at defenders at speed, checks, weaves this way and that, and is always hard to dispossess.

"Vertical" is what they call Iniesta in Spain. That is what the whole team are, combining the Spanish virtue of holding on to the ball, of engaging in high-speed formation dancing, with a direct purposefulness, sights always set on the opposition goal.