McLeish handed full debuts to Ecuadorian pair Christian Benitez and Giovanny Espinoza in Tuesday night's 2-1 Carling Cup win at League One Southampton.
Grizzled English midfielders Lee Bowyer and Lee Carsley may have grabbed the goals which sent Brum through, but the exotic new boys also impressed.
Striker Benitez - the Blues' £7million record signing - was a constant threat, rattling the inside of the post with a rasping drive and also setting up Bowyer's opener, while Espinoza put in a solid shift at centre-half.
"Due to injuries we had to ring the changes but the players who came in did well," said McLeish.
"Chucho (Benitez) made his first start and was unlucky not to score.
"It was Giovanny's first game in England and he knows what it's all about now - big centre-forwards getting in your face.
"It's not South American style which is more tactical and more into feet. There's a lot of aerial stuff in this country but he'll get used to it."
McLeish now turns his attention back to the Premier League and Saturday's trip to Harry Redknapp's in-form Tottenham.
The north Londoners have made a spectacular start to the season but White Hart Lane holds happy memories for McLeish after Birmingham secured a 3-2 win in his first game in charge two seasons ago.
"I hope they've forgotten about that and won't be talking about revenge or anything," said the Scot.
"I hope we give as good a performance as we did at Manchester United, and hopefully get something this time.
"They've had a brilliant start. We know what we face there, they have captivated the country with their imaginative football and we know we are in for a game.
"What they can achieve depends if Harry keeps them all fit. I know he already has a massive squad compared to ours - his second team would probably be worth £50-60million.
"He's certainly got the riches, but Harry builds a team ever so cleverly. They must feel they have as good a chance as anybody if they avoid injuries and suspensions they certainly have the personnel."
McLeish hopes to have added Sporting Gijon's Spanish midfielder Michel, 23, to his squad ahead of Saturday's game.