Blaise Matuidi admitted that "distressing" injuries to David Luiz and Thiago Motta had taken the shine off Sunday's dramatic 3-2 victory at Marseille.
The French champions twice fell behind at the Stade Velodrome, with Andre-Pierre Gignac bagging a double for the hosts, but Matuidi and Marquinhos drew Laurent Blanc's men level on both occasions.
An own goal from Jeremy Morel ultimately decided an absorbing Classique in PSG's favour, thus allowing the capital club to return to the top of Ligue 1.
However, Matuidi admitted that the victory had been soured by the loss of David Luiz and Motta to suspected hamstring tears.
"It was not easy to win this game," the midfielder told Canal Plus . "In this game, unfortunately, we lost two players. For the rest of our season, it is distressing.
"Otherwise, we are very happy to win here against a good Marseille team. It was important to take the top spot.
"But it will be hard to win this league right until the end."
The injuries are particularly concerning for PSG, who sit one point clear of Lyon at the summit of Ligue 1, as they face a two-legged Champions League quarter-final clash with Barcelona later this month.