Lionel Messi will miss PSG's away game at Metz after picking up a knock to his left knee, the club have confirmed.
Messi underwent an MRI scan which confirmed the signs of bone contusion. A further update regarding his fitness will be released in the next 48 hours.
PSG host Montpellier on Saturday before they face Manchester City in the Champions League on September 28.
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Messi was substituted by manager Mauricio Pochettino in the 76th minute during his home debut against Lyon on Sunday.
The decision appeared to frustrate the 34-year-old Argentine who did not shake hands with his boss when he left the pitch.
Pochettino defended his decision after the match. He said: "Sometimes it pleases people, or it doesn't. I asked him how he was, and he said he was fine."
Messi is yet to score so far in his three PSG appearances.
PSG currently sit top of the Ligue 1 table on 18 points after six matches, five points ahead of second-placed Marseille.
Marco Verratti is back in training while Sergio Ramos - who is still yet to make his PSG debut after moving from Real Madrid in the summer on a free transfer - is training individually as he steps up his recovery.
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