Swansea captain Ashley Williams condemned Eden Hazard for the incident which led to the Chelsea man being sent off during the Capital One Cup semi-final clash at the Liberty Stadium.
Chelsea, 2-0 down from the first leg, missed out on a trip to Wembley after the second leg ended in a goalless draw.
And Hazard was red-carded with 10 minutes remaining after kicking out at a ball boy who appeared to refuse to give the ball back after it went out of play.
“Demba Ba told me the ball boy held onto it but I saw him kick him and you can’t do that to a young boy,” Williams told Sky Sports.
Swansea manager Michael Laudrup said: “I think Hazard, who is a great player, will regret it when he sees it.
“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.”
More reaction to follow later.