Manu Fernandez/Associated Press

Last season, when Paris Saint-Germain were faced with financial fair play (FFP) restrictions, they made the decision to spend their entire budget on one player. Regardless of the success they achieve this year, it was a risky move—one that nearly backfired.

If the club want to progress and continue to grow, they need to avoid making the same mistakes again in the summer transfer window.

Signing Paul Pogba, as discussed in this column, would be the dream signing, but it wouldn’t address a number of more important issues in the current squad.

FFP would demand that players were sold in order to finance a deal for Pogba, leaving the squad shorter than it already is now. During the month of April, when the club were fighting on four fronts, a number of injuries and suspensions showed the weak underbelly of Laurent Blanc’s squad.

One example of how to build a successful squad is Jose Mourinho at Chelsea. His game plan has always been to have two players in every position, as quoted in the Daily Star back in 2013.

“We have that (balance in the squad). We have two players per position, with three strikers and an extra midfield player.

“Every position is covered and we are very happy with what we have.”

It’s hard to argue against a coach that has been so successful. If we apply that same model to the current PSG squad, they are already three players short.

There is no third forward, and they are missing two midfielders.

PSG Squad 2014/15 GK Sirigu Douchez RB Van der Wiel Aurier LB Maxwell Digne CB Thiago Silva Marquinhos CB David Luiz Camara CM Verratti Cabaye CM Thiago Motta Rabiot CM Matuidi ??? ??? FW Pastore Lavezzi FW Cavani Lucas CF Ibrahimovic Bahebeck ??? BR/UK

Going into next season, there are six players with question marks hanging over their heads. Gregory van der Wiel has been linked with Manchester United, as per the Express. The Guardian suggests that left-back Lucas Digne may be on the move this summer.

Yohan Cabaye’s future has been up in the air after a poor season in Paris, and Liverpool’s Brendan Rodgers is a fan, says the Daily Mirror. Then you have the constant stories linking Ezequiel Lavezzi and Edinson Cavani with moves away this summer.

At 36 years old, veteran defender Zoumana Camara needs replacing. He does bring experience to the squad, but when Blanc preferred to bring on an unfit David Luiz against Barcelona, rather than Camara, it shows his limitations.

The other doubt for next season is Thiago Motta. After some fantastic performances last year, he has struggled with injuries and to find form. He could still be an experienced squad member, but it’s hard to envision him in the starting lineup every week.

Not every one of these players linked with transfers will move in the summer, but it’s difficult to see them all remaining. If the squad is three players short at the moment, anyone you sell has to be replaced.

PSG’s first priority should be to add in the areas they are weak, so a central midfielder would be a priority. However, you don’t just want a squad player. To improve a team, you need to buy someone who is capable of starting, which gives you a stronger unit.

Thibault Camus/Associated Press

That would give Blanc another problem: keeping everyone happy. This means you have to sign the right player, with the right attitude. It remains to be seen if Adrien Rabiot will be happy to spend another season as fifth/sixth choice.

Buying David Luiz last season has left PSG in a hole. It will likely take a couple of seasons of smart spending to get the squad to the level they would like, and that doesn’t involve spending big on any of the marquee names they have been linked with.

First, they need to plug the gaps, and then they need to add quality. When you are trying to push into the latter stages of the Champions League, it can be a difficult job. However, teams like Juventus and Monaco showed you can get there by making smart rather than extravagant moves.

PSG need to follow that mantra this summer, rather than be tempted by shiny new toys.