Paris - Paris St Germain suffered an injury setback to their defence when first-choice centre back Thiago Silva sustained a thigh injury during an early-season friendly on Monday.
The Brazil international limped off after 14 minutes of his team's 2-1 win at Napoli and will undergo medical checks on Tuesday.
"It's probably a small tear in the back of his (right) thigh. I hope it's not too serious," coach Laurent Blanc was quoted as saying in French sports daily L'Equipe on Tuesday.
Defending champions PSG, who drew 2-2 at Stade de Reims in their Ligue 1 opener last Friday, take on Bastia at the Parc des Princes on Saturday.