The wait is over. A week-and-a-half after joining Paris Saint-Germain, Lionel Messi could be set to make his debut against Brest on Friday.

Following his shock exit from Barcelona as a free agent, Messi became the Ligue 1 giants' fifth major signing of the transfer window, joining the superstars Mauricio Pochettino already had at his disposal.

Messi, alongside his former Barca star Neymar, has been training this week, and though Pochettino refused to confirm his squad during Thursday's news conference, it is expected the duo will play a part.

With Kylian Mbappe already back, here's how Pochettino could set out at Brest.

GK: Keylor Navas

Navas has been one of Europe's outstanding goalkeepers in recent seasons, ranking third for goals prevented (8.1, using expected goals on target data) in the top five leagues in 2020-21. Gianluigi Donnarumma – the Player of the Tournament at Euro 2020 – did not leave boyhood club Milan just to sit on the bench and, at 22, represents the long-term option, but after only just returning to training, it is likely Pochettino will stick with the former Real Madrid goalkeeper for Friday's game, though the ex-Spurs boss did suggest Donnarumma may be available. 

RB: Achraf Hakimi

Alessandro Florenzi headed back to Roma at the end of his loan, but PSG identified just about the best replacement on the market. Over the previous two seasons, Robin Gosens (34) was the only defender with more goal involvements than Hakimi (30), who scored on his first Ligue 1 appearance.

CB: Marquinhos

PSG won 72.5 per cent of the games Marquinhos played last season in all competitions, conceding 0.7 goals on average. Those numbers altered significantly in his absence, with a winning percentage of 52.9 while shipping 1.1 goals per game. Even with the club's superstar signings, their captain remains one of the key men. Even though he has just returned from an extended break following Brazil's Copa America exploits, it would not be surprising to see the former Roma man thrown straight back into the fray given PSG have conceded three times across their opening two matches.

CB: Presnel Kimpembe

Sergio Ramos, another freebie, may no longer be able to play every game – he appeared only 15 times in LaLiga for Real Madrid last term – but PSG better hope he is there for the big ones. However, the 36-year-old will not be available until September, meaning France defender Kimpembe is likely to continue in the heart of defence for now. He made a game-high four clearances in last week's 4-2 home win over Strasbourg.

LB: Abdou Diallo

This is perhaps the one position on the pitch where PSG lack a genuine world-class option. Even if Pochettino were to bring in Kimpembe as a third centre-back, there is no outstanding left-sided wing-back. Diallo, a defensive full-back in an attacking team, gets the nod by virtue of starting the season fit and ahead of Layvin Kurzawa in the pecking order, while he also assisted Mauro Icardi's opener against Strasbourg.

CM: Ander Herrera

At the end of a season in which Marco Verratti was restricted to only 16 Ligue 1 starts, Euro 2020 provided a reminder of his talents. The Italy midfielder created a tournament-leading 14 chances across just five games while still completing 93.1 per cent of his 417 passes. However, it seems likely we will have to wait to see the playmaker link up with Messi, as he too is only just easing his way back into training. In his place, Herrera seems set to carry on in midfield and, in truth, is a more than able back-up. He attempted 100 passes on matchday two, completing 94 of them.

CM: Danilo Pereira

Leandro Paredes, Messi's international colleague, was trusted for the big occasions in the Champions League. However, he has just returned to training after helping Argentina win the Copa America, while Idrissa Gueye has been out due to COVID-19 protocols. Youngster Eric Ebimbe started against Strasbourg but was replaced by Pereira after an hour, and the towering Portuguese would add some presence in the middle of the park.

CM: Georginio Wijnaldum

Angel Di Maria would be very unfortunate to miss out on a full-strength XI and undoubtedly still has a part to play even with Messi in place, but he too is only just back from international duty. Wijnaldum has featured in both of PSG's Ligue 1 games so far and across his Liverpool Premier League career, led all Reds midfielders in recoveries (951) and duels won (645) and ranked second in interceptions (115) and third in tackles (181).

RW: Lionel Messi

Of course, Messi can play across the front three, but starting from the right – with Hakimi in the Dani Alves role outside him – will bring back memories of Barca teams of old. It is the role he occupied in 2014-15, forming part of perhaps the Blaugrana's most exciting attacking trio, which of course Neymar was also part of.

CF: Kylian Mbappe

Mbappe has the Luis Suarez role, providing the direct runs in behind that create space in front of the defence for Messi and Co, and a video of the two stars linking up in training went viral this week. Last season's 53 goal involvements did not quite match the forward's career-high of 54 in 2018-19, but Mbappe can expect to break all sorts of records in this thrillingly creative line-up this term. He already has two Ligue 1 assists to his name this season, and that is without playing alongside two of the world's best players.

LW: Neymar

Still the world's most expensive player if no longer the biggest name in his own dressing room, Neymar was the third member of that 2014-15 front three. Having decided to step out of Messi's shadow, the Brazil superstar wanted his old friend back. During their four years together at Barca, Neymar assisted Messi 22 times, while the six-time Ballon d'Or winner returned the favour on 20 occasions, and surely the chance to have this sensational front three starting together will be too tempting for Pochettino to turn down – even if it is harsh on the in-form Icardi.