REIMS, France, Aug 29 (Reuters) - Lionel Messi was named on the substitutes" bench when Paris St Germain take on Stade de Reims in Ligue 1 on Sunday, but coach Mauricio Pochettino said the Argentine forward could play a part in the game. "He is going to be on the bench, he arrived later, he is working hard," Pochettino told official broadcaster Amazon. The 34-year-old Messi, who joined from Barcelona earlier this month on a two-year contract, could play in a competitive game for the first time since winning the Copa America with Argentina on July 10. "He could have some minutes," Pochettino said. Kylian Mbappe, who has yet to extend his contract that expires next June amid buying bids from Real Madrid, will start up front alongside Neymar and Angel Di Maria. PSG have a maximum nine points after three games in Ligue 1.