The midfielder appeared to kick the youngster late on in the match when he failed to return the ball quickly, an incident that earned him a red card.
Laudrup admitted that the ball boy was wrong for withholding the ball, but refused to condone the Chelsea man's actions.
"I think Hazard, who is a great player, will regret it when he sees it," BBC Sport quotes him as saying.
"The ball boy should have let the ball go but he was pushed first and then he kicks him.
"As a player when you are behind your pulse is very high and sometimes you say and do things, you overreact. But there are some things you cannot do."
Swansea progressed to the final of the competition 2-0 on aggregate following the 0-0 draw at the Liberty Stadium.