Paris Saint-Germain "do not have a choice" but to send Neymar for surgery on his fractured foot, according to club president Nasser Al-Khelaifi.
Neymar suffered an innocuous-looking injury in Sunday's 3-0 Ligue 1 victory over Marseille in Le Classique, riding a challenge from Bouna Sarr before awkwardly planting his foot in the turf.
He sustained a sprained ankle and fractured metatarsal during the incident, before leaving the pitch on a stretcher and in tears.
Coach Unai Emery was initially hopeful he could feature in the Champions League last-16 second leg against Real Madrid on March 6, insisting in a news conference on Tuesday that no decision had been made regarding surgery.
But the club revealed on Wednesday the Brazilian will require an operation, and Al-Khelaifi admitted there was little choice.
"We are very sad about this news," Al-Khelaifi said in the wake of PSG's 3-0 Coupe de France win over Marseille.
"But it [surgery] is the best decision for him, for the club, for the national team of Brazil. We do not have a choice.
"We made the decision together. It's not good news, but the players showed [on Wednesday] that they wanted to play harder together.
"We will do it together, with the players and the fans. The match against Real Madrid is very important.
"It's the game of the season, as we want to qualify for the quarter-finals. We will qualify. We have the team and the players who are able to do it. We will work together."
Despite reports claiming Neymar could be out for two months, Al-Khelaifi is hopeful of him returning in time for the Champions League quarter-finals - scheduled for the first week of April - should PSG get past Madrid.
"We made a meeting with Brazil's doctor, our doctor, the family, the player," he added. "Everyone agreed with the decision to operate on Neymar.
"It was a difficult decision. We could not take the risk of delaying the operation. We do not want to waste time, so we hope he will be ready for the quarter-finals of the Champions League."