A routine sample of Kenny's urine taken after the Blades' clash with Preston in May 2009 was found to have traces of banned substance ephedrine present.

This led to United suspending the player on June 4 and he was then banned by the Football Association.

Kenny admitted the charge and a Regulatory Commission hearing on Monday ruled that the Republic of Ireland international would be suspended for a nine-month period, back-dated to July 22 when the Football Association's ban took effect.

Blackwell insists the commission accepted that Kenny did not deliberately cheat and now looks likely to consider an appeal.

Blackwell told Sky Sports News: ''We know Paddy's not a drugs cheat and they've accepted that.

''We're just considering our options. We think nine months for a mistake out of a medicine chest seems harsh.

''We'll consider our options. That's down to the legal people.

"It was a long day and at the end of it they accepted it wasn't taken to enhance sporting performance.

''If you've got a bad chest and you take something to relieve pain it isn't going to make you quicker, faster, taller.''

Blackwell went on to warn all professional athletes of the dangers of taking over-the-counter remedies without consulting doctors.

He added: ''Players have to take responsibility for their lives and actions but new regulations which have come in in the last couple of years mean a player can be pulled in at any time.

''If you're not feeling well, make sure you check every detail (with medicines) because the ramifications for anyone caught breaking the rules are very severe.

''It's a lesson for every professional footballer and athlete now, with the Olympics coming up, they're very hot on it...I think you'll see the authorities really clamping on it.''

The Regulatory Commission chairman Christopher Quinlan said after the hearing: ''The Regulatory Commission considered carefully the evidence and the submissions from both parties.

''Whilst we found that the player satisfied us on the balance of probabilities that the substance was not taken with the intention of enhancing sporting performance, his admitted conduct displayed significant fault.

''A professional sportsman, including a football player, has a strict responsibility to ensure prohibited substances do not enter his/her body.

''In this instance Mr Kenny knowingly ingested an over-the-counter medicine above the prescribed dosage without reading the accompanying package or leaflet and without reference to his club's doctor or other medical staff.

''It is incumbent upon all professional footballers to understand the perils and dangers of so doing and to act in the way he did, contrary to the Doping Control Programme delivered by The FA and in any event what should be a matter of common sense for a professional sportsman, showed in our judgment a complete disregard for those responsibilities.''

Kenny will also be subject to 'target testing' for the next two years.