UEFA opened an investigation on Thursday following Manchester City manager Manuel Pellegrini's outburst against the referee who oversaw his team's 2-0 Champions League defeat to Barcelona this week.

Pellegrini said after the first leg of their round of 16 tie that referee Jonas Eriksson "decided the game" when he sent off Martin Demichelis for a foul on Lionel Messi, who then scored from the penalty spot. Pellegrini also questioned the referee's partiality and competence.

UEFA said in a statement that a disciplinary inspector has been appointed to examine the case. "Based on the outcome of this investigation, a decision will be taken on whether disciplinary proceedings will be opened," the governing body said.

Barcelona have history with Eriksson, who was criticized by then-coach Pep Guardiola for not awarding his team penalties in 2012 in a 0-0 draw at Milan in the quarter-finals. Pellegrini, who faces a fine or touchline ban, said he felt Eriksson was trying to make amends for "an important mistake against Barcelona in a previous match."

Pellegrini also confronted Eriksson after the game, which saw Dani Alves add a late second goal. "He did not have any control of the game," Pellegrini said. "It was not a good idea to put a referee from Sweden in (charge) of such an important match. ... Maybe that kind of game needs a referee with more experience."