Czech defender Martin Jiranek and former Arsenal midfielder Alexander Hleb - if he passes a late fitness test on an ankle injury - will be in contention for Sunday's home clash with Liverpool.
Chilean Jean Beausejour also arrived on transfer deadline day although he will not join his team-mates until next week as he waits for visa clearance.
With Ben Foster and Nikola Zigic signed earlier in the summer, McLeish has the kind of competition he craves.
McLeish said: "There's a good spirit in the dressing room. I've said that time and time again since I came here.
"It's been evident again this season, although we've got new players and we're trying to integrate them.
"But, as you build a team and you build a club, there's more competition for places and the players have to play to their very best level.
"The thing that motivated me most was the fear of losing my place and I hope that the players here can respond in the same manner."
McLeish anticipates Liverpool challenging near the top of the table this season under Roy Hodgson.
But he is calling on his players to repeat the impressive form they showed at home last season against the leading sides.
Blues shared the spoils at St. Andrew's with Chelsea, Manchester United, Arsenal, Tottenham, Manchester City and Liverpool whom they are unbeaten against in their last eight league meetings.
McLeish said: "Barry Ferguson is right to say we fear nobody but we can't leave that in the dressing room.
"We have to go and perform against a club of Liverpool's magnitude.
"Last year we had a good campaign against the bigger clubs here at St. Andrew's, aided and abetted, of course, by a hostile crowd.
"I'm looking for the crowd to be at their very best again this season.
"I expect Liverpool to be up their fighting with the best teams for the title and for the top four, of course.
"Under Roy's tutelage I'm sure they will get better, but hopefully it takes them a couple of weeks yet!"
Veteran striker Kevin Phillips (thigh) and defender Stuart Parnaby (hamstring) remain on the sidelines due to injury.