French superstar Kylian Mbappe was reinstated in Paris Saint-Germain's first team on Sunday after being sidelined for several weeks amid an ongoing contract dispute.

PSG opened their Ligue 1 title defense with a goalless draw at home against Lorient on Saturday as the team's prize asset watched from the stands.

"After very constructive and positive discussions between Paris Saint-Germain and Kylian Mbappe before the PSG-Lorient match, the player was reinstated in first-team training this morning," PSG said in a statement.

After a summer of flux at the Parc des Princes filled with new arrivals and Lionel Messi's departure, it is the Mbappe stand-off that continues to dominate the headlines.

The France captain has refused to sign an extension to his PSG deal, meaning he can leave for free next year, with Real Madrid long seen as his preferred destination.

Qatari-owned PSG wants to sell him now and bring in a significant transfer fee for a player who cost 180 million euros ($198 million) from Monaco in 2017.

"The position is very clear. If Kylian wants to stay, he must sign a new contract. We can't let the best player in the world today leave for free. It's impossible," PSG president Nasser al-Khelaifi said last month.

Mbappe has not been allowed train with the first team and played only one of PSG's five warm-up games and was not invited to the pre-season tour in Japan and South Korea.

New coach Luis Enrique on Friday said he hoped a solution could be found, but Mbappe has not been allowed to train with the first team and was left out of the squad to face Lorient.

Instead he sat alongside fellow 2018 World Cup winner Ousmane Dembele, who completed his transfer from Barcelona earlier in the day, as Luis Enrique handed debuts to six players.

Despite his sidelining Mbappe was one of the first to welcome Dembele.

"Welcome home my brother, so happy to see you here, the adventure begins," Mbappe posted on social media.

The two friends then appeared smiling together in the stands while Brazilian star Neymar, whose future is also in doubt, was absent because of a "viral syndrome".

With his reinstatement, Mbappe has partly won his case, even if it is too early to know if it will lead to the contract extension the club is demanding.

Saturday's offensive weaknesses against Lorient may have prompted PSG to soften their attitude toward the top scorer in the club's history.

The 24-year-old forward is now available for the trip to Toulouse on August 19, even if he has played just once, a friendly against Le Havre, in the past two months.