The midfield loanee had a Pompey bow to forget as he was dismissed in Saturday’s disappointing 1-0 loss at Shrewsbury.
McCrorie was given a second yellow card in the 81st minute as he caught winger Donald Love late and will now serve a one-game ban.
Kenny Jackett explained the 21-year-old made no excuses for the tackle after he walked.
But the Blues boss feels the summer arrival has to learn the cost of letting his frustrations boil over in such a manner.
That was a likely factor in the incident as the Blues chased the game, despite having the lion’s share of territory and possession.
Jackett said: ‘I asked if he caught him and he said he did.
‘He’s put the referee in a position to be able to give him a second yellow.
‘It’s a learning experience for him. Frustration can’t be shown like that because it’s put us down to 10 men and now he’s going to miss a game.’
Referee Charles Breakspear set an early precedent for handing out cards on Saturday, with eight cautions given out in total.
And there was plenty of stoppages to contend with, but Jackett wasn’t prepared to use excuses for his side’s shortcomings.
He added: ‘There was a lot of stops and free-kicks both ways. They time-wasted and slowed the game down, and fair play to them it worked.
‘We can analyse the referee’s performance but I don’t think there were any major incident I could complain about.’