Paris Saint-Germain (PSG)'s extraordinary transfer window has been well-covered, with the club having signed Lionel Messi, Gianluigi Donnarumma, Georginio Wijnaldum, Sergio Ramos and Achraf Hakimi.Mauricio Pochettino's team are comfortable favourites to win Ligue 1, having lost the title to Lille by a solitary point last season. They have enjoyed a good start to their 2021-22 league campaign, but sterner tests await.The club could soon lose star forward Kylian Mbappe, with the Frenchman edging closer to a move to Real Madrid. It remains to be seen if and whether PSG decide to replace him.Kylian Mbappé deal. PSG director Leonardo answers to La Sexta: “The only thing I can say is that nothing has changed compared to the last two days. It's the same situation”, he said to @sebaquadrelli. ⚪️🇫🇷 #PSG #MbappéReal Madrid are working on it. Talks ongoing.— Fabrizio Romano (@FabrizioRomano) August 27, 2021On that note, here's a look at PSG's possible line-up for their Ligue 1 game against Reims on Sunday.Goalkeeper - Gianluigi DonnarummaGianluigi Donnarumma is all set to make his PSG debut.Gianluigi Donnarumma was on the bench against Brest, with Costa Rican shot-stopper Keylor Navas starting the game.Donnarumma and Navas are two of the best goalkeepers in the game, so it will be interesting to see how manager Mauricio Pochettino proceeds with this situation. The younger Donnarumma is a bonafide superstar, having played a pivotal role in Italy's Euro 2020 triumph and receiving the UEFA European Championship Player of the Tournament award.Gianluigi Donnarumma starts his first PSG game on the bench 🪑 pic.twitter.com/H3CXtEKlQc— Goal (@goal) August 20, 2021The 22-year-old has arrived at PSG on a free transfer, and it is very likely the Ligue 1 giants will end this season with Donnarumma as their no.1. Navas deserves better, having been replaced at Real Madrid by Thibaut Courtois despite winning three Champions League trophies in a row. But he looks set to step aside for Donnarumma and assume second fiddle.You may also like: Fabrizio Romano Exclusive: 5 biggest transfers that could happen before deadline day.