Why Ferguson has bought £18m Young, the League's most versatile player

Manchester City fans will not be best pleased but it was their first-team coach David Platt who unwittingly set United's £18million signing Ashley Young on the road to success.

Young, whose versatility means United got four players this summer for the price of one, makes his competitive debut for Sir Alex Ferguson at West Brom on Sunday.

Fitting in: Young (right) and Chris Smalling are the future of United

But he was a diminutive 16-year-old struggling to win a full-time contract at Watford when England Under-21 manager Platt changed his fortunes by ringing the club out of the blue looking for a spare body to help out with a training session for his squad.

Watford's academy chief at the time, David Dodds, was aware of Young's football brain but uncertain his frail physique would allow him to be a full-time professional.

He drove the excited youngster to the nearby England camp and then watched stunned as Young caught the eye in a full-blooded practice match against far more experienced performers like Michael Dawson.

Talent spotter: David Platt bought Young to Watford

'It's something I will always remember,' says Dodds.

'David Platt rang asking if we could provide a player to help with the England training at Slough. Ashley was a non-contract player with us, but he was bright about the game so I drove him down. They gave him an England strip and he played in an 11-v-11 game. I have to be honest, he really didn't look out of place.

'He arrived at the session as just a lad making up the numbers but he left as someone we knew might have a real future in the game. He took away an England strip to keep and I remember his excited phone call to his mum on the way home to tell her what had happened.'

It proved a huge turning point for Young, whose early days at Watford were hampered by his size, having initially been discovered by scout Chris Cummings.

Dodds reveals, however, that Young's slender frame meant he played in a number of different positions at the Watford academy - discovering a versatility that is going to be crucial to Ferguson this season as he aims to retain the League title and wrest the Champions League from Barcelona.

Burgeoning star: Young honed his talent at Vicarage Road

'Even then, Ashley would play wide right, wide left or behind a striker where he could find pockets of space. There was no great secret or masterplan to it, we just put him in positions where he wouldn't get physically knocked around because he was so small and slight.

'He had a bright football brain but although he was 16, he was physically like a 14-year-old.

'After that England training session, he started to become more effective for our Under-17s, he played like we see some of the Spanish boys, Xavi and Iniesta. He spotted passes early and started to get quicker and more agile.'

Start of something big: Young stepped up the ladder when moving to Aston Villa

That fantastic football brain and ability to play with either foot means Young has blossomed in different positions - right and left wing, central midfield and second striker.

Gradually, the stages have got bigger and bigger; Watford, Aston Villa, now Manchester United and England.

Former Villa boss Martin O'Neill famously hailed his £8.5m signing 'a genius' after an injury-time winner at Everton.

And England manager Fabio Capello said he saw Young's international future in central midfield after he rescued England against Switzerland as a substitute at Wembley in June, equalising as they came back from 2-0 down to draw 2-2 in a Euro 2012 qualifier.

Genius: Martin O'Neill hailed his signing

Although 26-year-old Young did not come cheap, Ferguson knows he has bought great versatility.

If United have a Champions League game at Real Madrid followed by a home match against Wigan in the League, the manager will be able to use different formations - and Young can slot into them all.

'Ashley Young can play in different positions, definitely,' said Ferguson.

'I'm not saying that's going to happen because at the moment he's filling that position on the left-hand side very well.

'But there are options to play him on the right and off the front, even though I have Wayne Rooney, Danny Welbeck, Ryan Giggs and Dimitar Berbatov as well.

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'Having that versatility helps players in terms of being in the team consistently. John O'Shea was a defensive equivalent. He had more than one starting position and played something like 400 games for us.'

Ian Storey-Moore, Aston Villa's chief scout under O'Neill, who watched Young numerous times at Watford before the club signed him in 2007, is convinced Young will be more effective the higher the level he plays.

'When we saw him at Watford, he was a bit ineffective in some games chasing shadows, as their manager at the time, Aidy Boothroyd, wanted the team to be quite direct,' he said.

Wembley winner: Young drifts past Micah Richards in the Community Shield

'But we saw enough in his game to realise how good he could be. He had great technical ability and a turn of pace to get away from players. I watched him several times and then two or three times with Martin before he signed him.

'Ashley came on a lot at Villa and I think he will fit in at United, playing with a host of quality of players. The good thing is, he gives Alex so many options because he plays in numerous positions, and play them well. He is a really good footballer.'