Verratti pulled out of the Italy squad during the international break due to an adductor injury and will again be unavailable as PSG seek to move to the summit of the French top flight, at least until Marseille host Bordeaux on Sunday, with victory at the Stade Saint-Symphorien.
The former Pescara man could be joined on the sidelines by Blaise Matuidi, who is doubtful for the encounter because of a hand problem.
"Verratti will certainly be missing against Metz, but we have hope he will recover quickly," said PSG boss Laurent Blanc.
"Blaise will be very tight."
However, there are no such problems for striker Zlatan Ibrahimovic, hampered by injuries throughout the campaign, with the Sweden international fit to play after being left out of his country's friendly with France on Tuesday.
"He [Ibrahimovic] has some soreness of course, but it makes sense," Blanc added. "He did a session before yesterday [Wednesday], recovering yesterday, he is now able to make the meeting. You will see him in the squad."
PSG sit second in Ligue 1, one point behind leaders Marseille, ahead of their encounter with a Metz side that has impressed upon the club's return to the top tier.
Metz are ninth on 18 points, six clear of the bottom three.
