UEFA’s Control and Disciplinary arm acted, apparently without any prompting from a Valencia official, following a 25th-minute tackle by Bowyer on striker Juan Sanchez during last week’s goalless first leg at Elland Road.

After reviewing video evidence UEFA then pulled no punches, roundly condemning Bowyer’s actions as they accused him of ‘‘assault’’ and ‘‘an illicit attack’’ in kicking Sanchez in the shoulder and then stamping on his chest.

Although Leeds have the right of appeal, one which they have already launched, it will not be heard until Friday, ensuring Bowyer is ineligible for tonight’s tie at the 53,000-capacity cauldron of the Mestalla.

It is understood the full weight of the Football Association will be behind Leeds, particularly should they reach the final, support which has apparently been gratefully accepted by United officials.

In truth, it is just the latest obstacle to be placed in front of Leeds during what has been a tumultuous season both on and off the pitch.

It has been United’s indomitable spirit which has seen them through to this stage, now only fortified by this latest drama, one which O’Leary and chairman Peter Ridsdale feel is an injustice.

‘‘This has come totally out of the blue and I am quite shocked he has been banned for three games, but the bottom line is he can’t play,’’ said a disappointed O’Leary.

‘‘I’ve spoken to Lee on the matter and he tells me he tried to step over their player. He is also shocked and upset because he wants to play in the big games.

‘‘But what we can do is try and get him to this great final because he deserves to play in it. All this has succeeded in doing is bonding the players closer together and there’s a sense of ’let’s do it for Bow’.

‘‘I hope that out of this adversity comes strength. There’s a great togetherness and spirit, which can only improve.

‘‘Things like this, when you have a spirit like ours in the camp, will pull them together even more although whether it will be good enough on the pitch only time will tell.

‘‘Obviously, I had a plan as to how we would play and that now changes with Lee out of the equation. With him out it is a blow because it is another one missing from the squad.

‘‘But then we’ve had plenty of hurdles just to get to here. It has still been a hell of an adventure up to this point I think the only people who haven’t been involved are NATO!’’

Ridsdale has admitted to feeling ‘‘a little bitter’’ about the situation, unsurprising given UEFA’s appalling sense of timing, with the hope the ban will be reduced to one match on appeal, so allowing Bowyer to play in the final in the San Siro on May 23 should Leeds get to Milan.

‘‘Frankly we’re stunned by a three-match ban,’’ said Ridsdale. ‘‘We saw nothing deliberate in the incident and we’ve said that to UEFA.

‘‘The referee (Pierluigi Collina) was congratulated by everyone for the way he handled the game.

‘‘Whilst we’re aware of why they (UEFA) re-looked at it there’s nothing to suggest it was deliberate and we think the ban is out of proportion.

‘‘Clearly we believe the ban is worth appealing against and we hope we can get to the final and the appeal will be successful and allow Lee to play.

‘‘I think the players are up for the game but they will feel very disappointed for Lee.

‘‘He’s had an outstanding season in the Champions League. He’s already scored six times and clearly had his eye on scoring more goals. Now UEFA have taken that away from him.’’

Eirik Bakke or Gary Kelly will now step in at right wing as Leeds look to secure at least the scoring draw which will guarantee their place in the final against Real Madrid or Bayern Munich.

But a record of 12 wins and four draws from Valencia’s 16 matches at home in the Champions League over the last two seasons, conceding just eight goals, paints a picture of just what Leeds are up against.

Undaunted, O’Leary added: ‘‘We’ve done our planning and we’ve just got to jiggle it without one person, so it’s no big deal. We’ve already had to play important away games in Europe without Lee this season.’’