PSG s head coach Mauricio Pochettino watches his players during the Champions League, round of 16, second leg soccer match between Real Madrid and Paris Saint-Germain at the Santiago Bernabeu stadium in Madrid, Spain, Wednesday, March 9, 2022. AP
The French giants led by two goals on aggregate in their last-16 tie with Real in midweek with less than half an hour to play.
But Karim Benzema scored a hat-trick as PSG imploded at a raucous Santiago Bernabeu, adding another embarrassing loss to their collapses at the hands of Barcelona in 2017 and Manchester United in 2019.
"How do I feel? Very upset," Pochettino told a press conference ahead of his side's league game against bottom club Bordeaux on Sunday.
"I have rage, I feel a certain discomfort. It's hard to sleep at night. But we have to take on our responsibilities and continue to think about the league.
"Personally, mentally, I'm in the process of recovery. That doesn't mean I'm not strong. I feel ready to fight and take up this challenge."
PSG's ultras have called for the club's management to resign for the first time since the Qatari takeover in 2011, citing the latest European failure.
They have said demonstrations will be held at the Parc des Princes on Sunday.
PSG have reached the Champions League knockout stage in each of the last 10 seasons, having only qualified for the competition at all five times in their history before the takeover.
"The atmosphere tomorrow will be the one our fans want," accepted Pochettino. "We understand their disappointment. They have the right to express their feelings."
The capital club are still romping towards a record-equalling 10th French title, sitting 13 points clear of second-placed Nice.
"The last few days have been difficult," added Pochettino. "We haven't had a lot of rest to regain energy.
"But we have a huge responsibility to finish the season in the best way. We have to win the title."
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