There was a time when Aston Villa supporters might have prayed that the antibiotics treating Stiliyan Petrov's recent chest infection would not have been strong enough to clear up the problem in time for him to play in the Carling Cup final.To say the large majority of Villa fans were hugely unimpressed by the £8m flagship signing Martin O'Neill made to lure the Bulgarian midfielder from his former club Celtic, when he took over as manager, is a huge understatement.
When O'Neill was forced to leave him out for over three months early in his career at Villa Park, supporters hoped that would be the precursor to Petrov's departure as an expensive failure.
Two years ago, they would have been delighted to write off the purchase price of another import from north of the border who was seemingly unable to cope with the demands of the Premier League.
Fortunately, O'Neill remained loyal to the man who helped him win every domestic trophy at Parkhead, when he could have cut him loose; now Wembley is the perfect venue for Petrov to reward that faith as Villa go in search of their first domestic trophy for 14 years.
"Leading the team out at Wembley is a great honour. It is a great thing and I am grateful to the manager for keeping faith with me. I came from Celtic for him, because I knew he could make me a Premier League player," said Petrov.
"It was hard for me to start with and I was left out of the team. He was truthful to me and that made me work even harder to prove myself. This is what I have worked for and this is what all the players have worked for."
Arguments can be made for several players as potential Villa match-winners. Brad Friedel's experience in goal will be vital along with central defender Richard Dunne's combative spirit and sheer refusal to accept defeat.
And Sir Alex Ferguson will be under no disillusions about the attacking menace of Villa's four England World Cup hopefuls Gabriel Agbonlahor, Stewart Downing, James Milner and Ashley Young, who will be more eager than ever to impress Fabio Capello on such a big occasion.
They are all important elements that will go a long way to deciding Villa's cup fate, but none will have more bearing on the game than the influence of Petrov, who has blossomed into the leader O'Neill always knew he was getting when he asked Randy Lerner for the funds to finance his arrival at the club.
Even fearful Villa fans drew a collective sigh of despair when Nani's wild two-footed tackle cut him down in the recent 1-1 Premier League draw with their Wembley opponents. Perhaps even United recognise him as Villa's most important cog in the wheel.
Petrov has blossomed since Gareth Barry's departure and has grown in stature as the club's captain and on-field general this season and his experience of the melting pot of Glasgow and huge games against hated rivals Rangers will be invaluable in the heat of the exchanges under the huge arch at Wembley.
Only Friedel and Emile Heskey have intimate knowledge of domestic cup finals and the remainder of O'Neill's emerging young team will be looking to Petrov for leadership amid the intriguing sub-plot of the Bulgarian contest with his international team mate Dimitar Berbatov.
"I want to help the young players in the game. It is very important to have players that have played in big games and finals and I want to win as much as Dimitar," said Petrov.
The pair will leave Wembley together on Sunday to join up with their national team ahead of next week's friendly against Poland and Petrov is desperate to be buckling his seat belt with a winners' medal around his neck.
