Paris Saint-Germain (PSG) had a fabulous transfer window at the start of the 2021-22 season. Big names such as Lionel Messi, Sergio Ramos, Gianluigi Donnarumma and Georginio Wijnaldum have strengthened their already fearsome squad.PSG hope new signings will result in Champions League gloryPSG have dominated League 1 over the past decade but are after an elusive Champions League trophy. With these transfers, fans will hope that they can finally get their hands on the continental award.Paris Saint-Germain@PSG_English🆕🎥The amazing unveiling of our new signings ❤️💙#NewDiamondsInParis 💎3:27 AM · Aug 15, 20215306967🆕🎥The amazing unveiling of our new signings ❤️💙#NewDiamondsInParis 💎 https://t.co/tVbJie45hFHowever, everything hasn’t gone according to plan for the Parisians. Several of their stars have put in sub-par performances and have struggled this season. Regardless, PSG seem to be well on their way to winning another league title.However, they will need their superstars to regain form if they want to taste success in Europe.Here we take a look at five Paris Saint-Germain players who need to regain their form in 2022.#5 Mauro IcardiMauro Icardi has struggled for PSG this season.Mauro Icardi joined Paris Saint-Germain from Inter Milan with a high reputation. His first spell with PSG was a loan move, wherein he scored a commendable 20 goals in 34 appearances in all competitions. The forward was then signed permanently in 2020 but could not replicate his earlier form.Icardi, who scored 124 goals in 219 appearances for Inter Milan, was initially called upon to replace Edinson Cavani. However, a certain Kylian Mbappe rose to stardom and has taken all the plaudits.Icardi began the ongoing season well with two goals in as many games but has since faltered and been dropped to the bench.GOAL@goalTwo goals in two Ligue 1 games for Mauro Icardi ⚽ ⚽Who needs Lionel Messi? 😅12:41 PM · Aug 15, 20215360222Two goals in two Ligue 1 games for Mauro Icardi ⚽ ⚽Who needs Lionel Messi? 😅 https://t.co/ZMl7C1dS9KHe has scored four goals in 15 appearances in Ligue 1 so far and if Icardi does not regain his form, life at PSG will be extremely tough. With familial issues prevailing, he is already under much scrutiny. The Parisians are looking to offload players as well, and the Argentine may be asked to depart sometime this month.#4 Gianluigi DonnarummaPSG summer signing Gianluigi Donnarumma.Gianluigi Donnarumma joined PSG at the start of the season from AC Milan in a transfer that drew quite a lot of criticism from the Milan faithful. The young goalkeeper has a lot more to see in his football career and can certainly become the best.A rising star, the 22-year-old goalie already has bags of experience under his belt. Donnarumma was crucial for Italy during their successful Euro 2020 campaign and won the Yashin Trophy, given to the best goalkeeper, in 2021. However, the Italian hasn’t had the same gratifying experience so far with PSG.Squawka News@SquawkaNewsOFFICIAL: Gianluigi Donnarumma won the 2021 Yashin Trophy with 594 points, 190 ahead of Édouard Mendy in second place.It was the largest margin of victory for any award at 2021 #BallondOr ceremony.5:14 AM · Nov 30, 20212046220OFFICIAL: Gianluigi Donnarumma won the 2021 Yashin Trophy with 594 points, 190 ahead of Édouard Mendy in second place.It was the largest margin of victory for any award at 2021 #BallondOr ceremony. https://t.co/fY8o9ztLaODonnarumma has kept just three clean sheets in eight appearances in Ligue 1. Additionally, Mauricio Pochettino seems to prefer Keylor Navas over the Italian as of late. The Italian will need to replicate his Euro heroics and remain consistent if he wants to cement his position at PSG.