McLeish believes City's recent demanding schedule finally took its toll on his players in Tuesday's 2-0 home reversal against Newcastle in the Barclays Premier League.
The Blues manager will make several changes for this weekend's FA Cup tie with Sheffield Wednesday ahead of the Wembley date with Arsenal on February 27.McLeish said: "It will be an opportunity for some players to be rested and recharge their batteries and try and get an edge back.
"There was definitely a flatness about some performances the other night after a fantastic month.
"We will look at that closely and the FA Cup will allow us to utilise the squad. There are some fantastic players to come into the team.
