Onegin, Royal Opera House, London

Just a couple of swells. And I don't mean their feet...

Summer may make most of us feel more Tiggerish, but for ballet dancers it's danger time: more are laid-off injured at this end of the performing season that at any other time in the year. Simple fatigue is the reason - injuries happen when dancers have to push themselves - and the Royal Ballet under Monica Mason has been trying to tackle the problem with more sensible schedules for its most popular dancers. Yet still some casts of Onegin have had to be scrambled: one night last week no fewer than five principals were not those the audience was expecting. How good, then, to find that Alina Cojocaru has pulled through an earlier foot problem to meet her scheduled appearances, which in turn has meant that the superb Johan Kobborg in the title role is up there too, offering a double dose of the kind of dramatic subtlety that makes a merely good ballet great.

Summer may make most of us feel more Tiggerish, but for ballet dancers it's danger time: more are laid-off injured at this end of the performing season that at any other time in the year. Simple fatigue is the reason - injuries happen when dancers have to push themselves - and the Royal Ballet under Monica Mason has been trying to tackle the problem with more sensible schedules for its most popular dancers. Yet still some casts of Onegin have had to be scrambled: one night last week no fewer than five principals were not those the audience was expecting. How good, then, to find that Alina Cojocaru has pulled through an earlier foot problem to meet her scheduled appearances, which in turn has meant that the superb Johan Kobborg in the title role is up there too, offering a double dose of the kind of dramatic subtlety that makes a merely good ballet great.

John Cranko's version of Pushkin's verse-novel has been in the Royal's rep only a couple of years, but already it feels established, its four meaty principal roles drawing new strengths from dancers. The challenge for management is to find two couples per cast that physically and temperamentally match. Olga and Lensky are young people who find love easy; Olga's older sister Tatiana, meanwhile, is a bundle of complexes, at once shy and absurdly romantic, hooked on a notion of her ideal lover while being hopelessly drawn to a cad. All this must be put across in the first few minutes by means of just one duet and a modicum of stage business.

Making her debut as Olga, Caroline Duprot gives a clean, sweetly nuanced performance that segues convincingly into the dangerous flirt who plays into Onegin's hands. Her Lensky, Federico Bonelli, has a lovely line and gracious manner, though I wish there were a bit more sincerity about him: it would make the duel that much more tragic.

But both characters are crude next to Cojocaru's Tatiana, who effaces herself in the opening scene, then lets rip with her imaginary beau in the mirror duet where her reckless physicality and some fabulous tricky dives leave spectators feeling as delirious as she is. The tiny 22-year-old has made great strides in the role since she first tackled it. She was always a good young Tatiana, but her older, married Tatiana looked flimsy. Now she finds a magnificent weight of bearing as the woman Onegin regrets turning down - she even looks plumper - which in turn gives her more authority when she rejects him.

Kobborg, too, has grown into his role. Always a complex reading, it has deepened into a true enigma. By the end of the ballet we are none the wiser as to the roots of the man's arrogance, cruelty and sheer disgustedness with life, but this Onegin is sufficiently evolved to keep us guessing.

jenny.gilbert@independent.co.uk

'Onegin': ROH, London WC2 (020 7304 4000), to 30 June. Big-screen relay to Victoria Park and Trafalgar Square, 17 June