Blanc's plea comes as PSG stuttered to a 2-2 Ligue 1 draw at home against Lille, with a second-half own goal from their opponents salvaging a point.
Blanc was happy with the team's general effort but disappointed by his player's effectiveness in front of goal with Ibrahimovic the only PSG player to find the net - Cavani missed the game due to personal reasons.
There is a bit of everything, regret and satisfaction on the back of the match," Blanc told Canal+.
"The regret is not getting into half-time with the lead.
"I am satisfied with the performance but I am disappointed with the result, although Lille could also have won.
"Our offensive potential is not limited to Ibrahimovic and Cavani - everybody must be efficient and effective; we have the players who have the potential to do better.
"This is a part of our game that needs to be improved in the second half of the season."
Lille counterpart Rene Girard was extremely proud of his players' performance, lauding them for coping with such an intense atmosphere.
"It was difficult to come here and I think we did the job well tonight," Girard said.
"If we had not been present with this physical impact and the intensity against this team you could have big disappointments.
"But it has been present and that is what is essential."
Lille remain four points in arrears of leaders PSG in third spot on the table.
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