#3 PSG have issues at left-back
PSG have had issues with their full-backs in recent years, a problem they have tried to address by signing right-back Achraf Hakimi from Inter Milan this summer for £54 million.
At left-back, though, they will have to rely on the injury-prone Juan Bernat and the inconsistent Layvin Kurzawa. Both Bernat and Kurzawa are not top-quality left-backs, and Bernat is recovering from a serious injury and made only three appearances in all competitions last season.
Centre-back Abdou Diallo can operate there, but it would be akin to a square peg in a round hole. PSG utilised young Dutchman Mitchel Bakker there last season, but the 21-year-old has been sold to Bayer Leverkusen on a permanent deal this summer.
AC Milan left-back Theo Hernandez was heavily linked with a move to PSG earlier this summer, but those rumours have since died down. AC Milan will not let go of Hernandez for cheap, and PSG's focus right now is clearly elsewhere.
#2 Less competition in Ligue 1
PSG failed to win the Ligue 1 title last season, losing out by a solitary point to Lille. That is unlikely to be the case this season, though.
With the arrival of Lionel Messi, the Parisien giants will boast arguably the best squad in the history of the game. A front three of Messi, Neymar and Kylian Mbappe would cause havoc against most defences in world football, so other Ligue 1 clubs have been suitably warned.
The Parc des Princes outfit will be overwhelming favourites to win Ligue 1. The French top-flight does produce exciting talents on a regular basis, but the quality of the competition is not very high.
The low intensity of the league could cost PSG the Champions League trophy. Against tougher opposition in Europe's premier club competition, PSG could struggle after playing out relatively 'easier' teams in the league.
#1 Imbalanced attack
An attacking trident of Kylian Mbappe, Neymar and Lionel Messi is easily the best in the game. Add to that the likes of Angel Di Maria, Mauro Icardi, Pablo Sarabia and Julian Draxler, and PSG have the ability to outscore most opponents.
However, despite the attacking prowess of Messi, Neymar and Mbappe, the trio doesn't contribute defensively. Given the world-class numbers the trio has produced over the years, that is understandable, though.
Pochettino likes his attackers to track back, but he may have to make some exceptions this time around. So it remains to be seen how that would affect the team's performances.