A FORMER Manchester United starlet who had his career wrecked by a high tackle had ''no guarantees'' of having a career in the game, a court heard today.

Ben Collett, then aged 18, had his right leg broken in two places by Middlesbrough's Gary Smith while playing in his first reserve team game for the Old Trafford club in 2003.

He was awarded £4.3 million in damages last August against Middlesbrough and Smith but today both the club and Smith challenged the size of the award at a hearing at the Civil Courts of Justice in Manchester.

Andrew Prynne QC, told a panel of three appeal judges Collett might not have made it in the Premier League and might have become a Championship footballer.

He also suggested the amount of the award had over-estimated Collett's earning potential if he had gone on to play in either of the top two divisions.

Despite Sir Alex Ferguson describing Collett as ''outstanding'' and a series of other footballers and ex-managers suggesting he had a future in the game, Collett was only ''on the cusp'' of becoming a first team player - and not yet established as a professional footballer, Mr Prynne said.

''It is expectations we are dealing with, against a background he had yet to prove himself.

''Each of the witnesses conceded, even the great Sir Alex Ferguson himself said his future was entirely dependent upon how he performed in the adult game.''

Mr Prynne cited the previous evidence of Sir Alex, saying ''every game was an audition'' and Howard Wilkinson, a former Leeds United and England manager, who said only ''very few'' young players are so outstanding you can say for certain they will become a professional - Wayne Rooney was one - David Beckham was not.

Mr Prynne said there were no guarantees and great uncertainties for young footballers.

He cited a statistical analysis of 147 19-year-old trainees at Manchester United - by the age of 25 only 31 per cent were still in the professional game at any level and by the age of 30 only 11 per cent.

The lawyer said while Collett stood a better chance than most young players of making the first team there was still a high drop out rate.

''You can't say for certain,'' he added.

''Because football at that level is a very uncertain game, both in relation to the player's future and their clubs.

''What it is not, is a claim in respect of someone entirely well established in a particular profession.''

Collett, now aged 23 and studying English at Leeds University, was present at the hearing with his father.

Collett, now 23, joined United's youth academy aged nine and signed youth contracts, becoming part of the club's FA Youth Cup-winning team in 2003.

Both Smith and the club had admitted liability for the ''negligent'' tackle.

Mr Prynne said it was wrong of the judge, Mrs Justice Swift, to base her estimation of the award on players' wages continuously going up.

Collett's award had been based, amongst other figures, on him earning £13,000-a-week on average until the age of 35.

But Mr Prynne said ''wage inflation'' could not be guaranteed, adding: ''The last year has taught us, if nothing else, that there is no certainty of rises continuing in any field.''

The appeal judges must now decide whether the size of the award is to be reduced but ultimately the money will be paid by Middlesbrough's insurers.

Lord Justice Carnwath, Lady Justice Smith and Lord Justice Hughes, decided to reserve their judgment and will give the ruling on the appeal at a date to be fixed in six to eight weeks' time.