The Slovakian defender conceded a needless penalty that cost Pompey a 1-0 defeat when he dived in and chopped down Chris Porter.
It was a rare mistake from the otherwise impressive centre-back and the Blues boss is confident he will choose to stay on his feet next time.
Appleton said: ‘To be fair to Lubo, he has done ever so well since he came here.
‘He had a rush of blood to the head the other night, which he is aware of.
‘I didn’t need to say a thing to him – the players did it for me.
‘It’s how he reacts to that now, which will be interesting.
‘Is he going to do it differently and stay on his feet more?
‘I’ve certainly seen a couple of good signs in training when he had opportunities to go to ground and he didn’t, so hopefully he has learned his lesson.
‘I would like to think he has got enough experience to bounce back.
‘He is 29, so it’s not as if he’s 18.
‘He’s a Slovakian international and he’s probably just as confused himself as to why he did it.
‘If he gets put in that situation again, hopefully he won’t make the same decision.’