Chelsea manager Rafa Benitez said that Hazard and the ball boy had exchanged apologies in the dressing room after the match.
Swansea defender Ashley Williams claimed he saw Chelsea midfielder Eden Hazard kick a ball boy in the second leg of their semi final in Capital One Cup tonight.
Hazard was sent off for violent conduct.
Swansea manager Michael Laudrup said Eden Hazard would regret his sending off.
"I think when he sees the incident on television, I think he will regret it," he told Sky Sports.
He denied that the club had instructed the ball boy, who appeared to lie on the ball, to waste time.
Speaking on Sky Sports, former Chelsea and England manager Glenn Hoddle said:
"Mark my words, the ball boys will have been told to do that.
"As a manager, if you've got ball boys, you will tell people instructing the ball boys that if you're winning the game, don't give the ball back quickly."