The Ligue 1 champions were hit with a fine of €60million earlier this month after breaching UEFA's Financial Fair Play rules and have had their UEFA Champions League squad reduced to 21 players for next season.
PSG have agreed to significantly limit their spending for the next two campaigns, but Blanc is still confident that the capital club will be able to improve their squad.
"Unfortunately for us, next year we'll be watched by UEFA," Blanc told Le Parisien and RMC Sport at the launch of a Nike store in Paris.
"So we will not be able to do what we want. I think we will be able to improve the team anyway. Do not forget that we have a team that has improved compared to last year and I think this will be the case next year.
"We already have a very good team in my opinion, so it does not take a lot of players. I think we'll get to do what we want to improve the team.
"We'll be working within UEFA's new constraints and want between two and four recruits."
Blanc also confirmed that winger Jeremy Menez, used sparingly this season, will leave the club and also hinted that defender Alex - whose contract expires at the end of next month - may depart as well.
"Menez will leave," Blanc added. "With Alex the matter is more complex, but we think he may leave.
"Perhaps there will be movement with players under contract. We will try to anticipate their intentions."
