The Scot, who guided the club to a first final at Wembley in a major competition for 55 years with their dramatic Carling Cup fightback against West Ham on Wednesday, has pointed out the successful signings he has made since Carson Yeung's arrival in 2009.
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Birmingham vice-chairman Peter Pannu suggested just four days before the semi-final with the Hammers that Hong Kong businessman Yeung had not received value for his £26.3million spend.
But Blues boss McLeish insisted his buys have not been flops. A ninth-place finish last season, the best for half a century, was proof of that, he said, but his new boys needed time to gel.
'When you bring in any signing, they don't necessarily go into your team straightaway, unless it is a big marquee arrival,' he said.
Happy days: Birmingham City manager Alex McLeish (L) celebartes with Barry Ferguson after beating West Ham
'I have had to build a squad and some of the new boys had to feel their way in and learn under the likes of Barry Ferguson.
'For instance, Craig Gardner came in. I said he wouldn't play in the first team to start with, but just about every single one of my signings are now in the team. Jean Beausejour did well when he came on, but he's had six weeks out with a knee injury. And big Nikola Zigic has done well, but he has taken time to adjust.
'(Spanish midfielder) Michel has been a big disappointment for me. I'm not disappointed with him, but I am disappointed I wasn't able to get him to adjust to the English game.
'And some signings are not signings which cost the earth but are signings you need to augment your squad.'
Cameron Jerome, Liam Ridgewell and Seb Larsson were the only three of the team that started on Wednesday who were not McLeish buys. And Zigic came off the bench to be the star turn, his height causing untold problems at the heart of West Ham's defence.
The Scot revealed that he had been sent an email of congratulations from Yeung, though the club owner was not at the game.
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Explore more:People: Craig Gardner, Barry Ferguson, Alex McLeish, Liam Ridgewell Places: Birmingham