Chelsea head coach Jose Mourinho described it as only "50 per cent of a goal" and claimed the best side on the night had lost.
Television replays were inconclusive and the row over the goal is certain to reignite the debate over the use of goalline technology.
But Chelsea skipper John Terry was adamant that Garcia's goal should not have been allowed to stand.
"I couldn't tell from where I was but a few of the lads said the ball didn't go over the line," he said.
"William Gallas was in the way of the ball from where the linesman was but he gave it, which was a bad decision.
"If you're not sure, then don't give a goal."
Striker Eidur Gudjohnsen, who missed a great chance to win the tie for Chelsea in the dying minutes, added: "I've been told by players who were closer than me that it was very debatable.
"William Gallas had his body between the linesman and the ball and I thought the official was in a very bad position to judge it.
"It was a brave decision to give a goal without being sure."
