Some talent is easy to spot. There is no great surprise in Real Madrid identifying Cristiano Ronaldo as a chap who can play a bit; in the same way it was not much of a stretch to picture Wayne Rooney in a Manchester United shirt one day. The radar of Harry Redknapp, the Portsmouth manager, homes in on different objects, however. Washed-up defenders, calamitous goalkeepers, strikers of uncertain years, these are Redknapp’s raw materials and to forge a creation of worth from such matter takes a rare talent.

Redknapp is well liked, but he has not always been well appreciated, not in a professional sense. Cast as a wheeler-dealer, a buyer and seller, it is rarely acknowledged how much emphasis he places on being able to play the game properly. At West Ham United, he fostered a generation of young players who went on to amass enough caps and trophies to fill a bank vault and at Portsmouth he has collected the flotsam and jetsam of Premier League football and shaped it into a successful, skilful team. At 61, the first trophy of his career is vindication of his methods, the frustration being where can he go from here?

Portsmouth will not win the Premier League, so, domestically, Saturday’s victory over Cardiff City at Wembley is probably as good as it gets. There is always the Uefa Cup next season, which, with further investment, could be a realistic target, but largely Redknapp will have to get his kicks from the sheer joy of building blocks; putting this player with that player, while much of the football world looks on perplexed. If there is a maxim that defines Redknapp’s transfer policy it is that class will out. He buys players of ability, regardless of age and, often, reputation. He trusts his instincts, sometimes against all logic, and at last this wit has repaid him with something tangible.

Portsmouth’s winning goal was scored by Kanu, the Nigeria striker, who is in his late forties, or at least he would seem to be, to judge from some of the wilder rumours that scorn his officially stated age of 31. He arrived on a free transfer from West Bromwich Albion, where he had just been relegated, in 2006. Redknapp’s contemporaries thought he was mad. Redknapp just thought the guy could play.

“He has great ability. That is the first thing I look for, every time,” Redknapp said. “With Kanu, I knew he still had something to offer. He was on a free, his wages were small, I wanted to give him a go. How old is he? About 47. He was in the dressing-room after the game saying, ‘Gaffer, gaffer, you give me a three-year contract.’ I said we’d talk about it on Monday.

“David James, I couldn’t tell you the amount of people who rang me when I took David James. I wouldn’t want to embarrass them. I had a few phone calls, all saying, ‘Are you mad?’ But he is a fantastic ’keeper and I had no doubts he was the best around. I knew what I could get from him.

“I had people trying to push a Ukrainian or whoever, but I wasn’t interested. I knew who I wanted. Sol Campbell was the same. All the phone calls: ‘He’s finished. What are you doing taking him? You must be off your head.’ I was aware of that game he had against West Ham United, when he really struggled, but after I met him, I knew that he still wanted to play and still had a point to prove.

“He walked away from Arsenal. How do you walk away from Arsenal? He had three years of his contract left, worth something like £15 million, and he walked away to join Portsmouth. I’ll admit it wasn’t the cleverest thing I’ve seen anyone do. Looking back, I don’t know why I did take him, behaving like that, particularly to come here on half the money. But I was up and down to London every day for about a week meeting him because I knew how much I wanted him to come. That was the key. He felt he wasn’t wanted at Arsenal, but I said I’d make him captain and told him how good he was and what he could do for us.

“Once I got Sol and David James I knew we’d have no more relegation battles. With those two at the back, I could enjoy the next year because there was no way we’d be going down. There is no secret to it. I get the best out of them because I treat them well, with a bit of respect. If they have a problem and need a day off, they get it. As long as they respond in the right way, that’s fine. I’m not a schoolteacher. I talk to a player and straight away I know whether he is up for it and whether he still wants to do something.

“Take Hermann Hreidarsson. He holds the world record for getting relegated at left back. When we were buying him, someone looked on the internet and said, ‘Harry, he’s been relegated more than any other footballer.’ I thought, ‘Oh, don’t . . .’ But he’s been great, Hermann.”

Portsmouth did not play Cardiff off the park, but nobody should have expected them to; Cardiff are a useful side under Dave Jones, with Joe Ledley exceptional again, and all the pressure was on the shoulders of Portsmouth as representatives of the Barclays Premier League. The occasion, and its long build-up since the semi-final victory over West Bromwich Albion on April 5, certainly took its toll on Redknapp, who almost had too much invested in victory after the recent death of Pat Lampard, his sister-in-law and the twin of his wife, Sandra.

“At the final whistle I just felt an overwhelming sense of relief,” he said. “Today was difficult because everyone thought we were going to win, but it has been a funny year for the FA Cup. So many upsets. It was difficult because Sandra has been so low, and when it’s hard for her, it’s hard for me. I so badly wanted to win to put a smile on her face. She knew how much it meant, so she’ll be happy today. That is the most important thing for me.”

Portsmouth’s victory was largely achieved at the expense of Peter Enckelman, the Cardiff goalkeeper, who was an accident waiting to happen and fumbled John Utaka’s cross in the 36th minute, presenting a gift to Kanu. Just 15 minutes earlier, Kanu had conjured the finest moment of the game, a turn of divine skill in the six-yard box that culminated in a spectacular miss, with the goal open. Enckelman’s flaw offered redemption and he took it, from a similar distance. Worth every penny of that free transfer, Harry would have smiled to himself. And not bad for 47, either.

Referee M Dean

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