Arsenal manager Arsene Wenger has welcomed the introduction of technology in the Premier League, but has said that a number of "absolutely disastrous" decisions have been made in this year's Champions League.
Borussia Dortmund progressed against Malaga to reach the Champions League semi-finals, but Manuel Pellegrini expressed his "bitter disappointment" as Felipe Santana's winner appeared to be offside.
Wenger admits he would like to see technology in the game expanded, so that offside decisions are also referred to systems similar to Hawkeye.
"When you look at the level of refereeing that you have seen again in Europe this week, it's absolutely disastrous what happened," said Wenger.
"In the same action, another player is offside and scores a goal, and we stand here and defend that? It's not defendable. Just because we do not want to progress and move forward. It's absolutely not acceptable.
"Controversy is not good for football. What is good for football is the right decisions."
It was announced yesterday that Hawkeye will be introduced in the Premier League at the start of the 2013-14 Premier League season.
