The former France international believes that the Paris-based outfit rely too much on their Sweden striker, and thinks head coach Carlo Ancelotti is yet to find his best system
The ex-Chelsea defender has warned the Ligue 1 table-toppers that they will need to find the right balance in the squad in order to challenge for the league title and that the role of attacking midfielder Ezequiel Lavezzi will be key.
"They are very dependant on Zlatan Ibrahimovic," he told LeParisian.fr.
"Carlo Ancelotti needs to find a system that suits him. When Ezequiel Lavezzi comes into the team it seems that his presence has a big impact on the players and balances the team a bit."
Desailly also discussed the club's current form and the pressure that they face because of their spending power.
"It is not easy for them," the former Chelsea star added. "The players must not buckle under the pressure of the fact that everyone expects them to produce great performances every time they play a game.
"The win against Troyes is a massive result because it was their first in three games in Ligue 1. The confidence they can take from this will allow them to go that little bit further in their next game."
PSG took top spot in Ligue 1 on Saturday with their 4-0 thrashing of Troyes, which put them above second-placed Olympique de Marseille on goal difference.