But McLeish, whose side host West Brom on Saturday, will only bring in players who can fit in with the current squad.
Blues' spirit and character have been key components in their success of the past two seasons and McLeish does not want that disrupted.
"I think this achievement (winning the Carling Cup) can be a spur," he said.
"If we continue to attract the right players, with the right character and determination, then you are always going to have a chance.
"The quality factor is very important to me. We really need to concentrate on bringing the quality in. But you just can't bring in a player of quality if he doesn't have the determination and desire that this group of players have.
"They have a fantastic spirit and never-say-die attitude."
Source: PA
Source: PA