Gundogan laments Barcelona exit from Champions League

Xavi: All decisions went against Barca in UCL exit vs. PSG (1:00)

Xavi Hernandez lashes out at the referee after Ronald Araujo's red card in Barcelona's 4-1 loss to PSG in the Champions League. (1:00)

Ilkay Gündogan lamented individual mistakes as Barcelona crashed out of the Champions League on Tuesday, saying the Spanish champions gave the game to Paris Saint-Germain "in the most simple manner."

Barça led 3-2 from the first leg in Paris and opened up a two-goal advantage in the tie when Raphinha gave them a 12th minute lead at the Olympic Stadium.

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However, the game swung after half an hour when Ronald Araújo was sent off for a last-man challenge on Bradley Barcola, with PSG coming back to win 4-1 on the night, advancing 6-4 on aggregate to set up a semifinal against Borussia Dortmund.

"I am very disappointed because we were in such a good position, not just after the first leg, but scoring the first goal as well," Gündogan told CBS. "Everything was in our hands and we just gave it away in the most simple manner. We just gave it to PSG and that is the most disappointing part."

Barça coach Xavi Hernández was fuming with the decision to show a red card to Araujo, labelling the performance of the referee a "disaster" and saying it completely changed the game.

Gündogan said the decision did condition the outcome of the match but did not criticise the on-pitch ruling.

"If he fouled him, I guess it's a red card," the Germany international added. "I haven't seen the replay. It's difficult to say, in these crucial moments, you need to be sure to get the ball.

"If you don't get it, and I don't know if he did, you have to stay away. I prefer to concede a goal there or to leave the striker one on one, even though he played the ball quite far ahead, so I don't know if he would reach the ball. But let the goalkeeper have a chance to save us or even concede a goal.

"To get a red card, to go a player down so early, it just kills the game."

Ousmane Dembélé equalised on his return to Barcelona after joining PSG for €50 million ($53m) last summer, with Vitinha then giving French champions the lead with a strike from the edge of the box after being left unmarked at a corner.

"Again [another] mistake," Gündogan added. "We have to step out there and don't let him shoot. He was so free.

"It's nothing we haven't trained, the closest man has to step out. Someone has to step out. No one did -- or did too late. Again, not necessary at all."

Kylian Mbappé added PSG's third goal from the penalty spot and then sealed Luis Enrique's side's passage to the final four in the 89th minute after Gündoğan had hit the post and had a penalty appeal turned down.

"Decisive actions, crucial situations, they will either reward you or punish you," Gündogan said. "Unfortunately for tonight they punished us."