The Sweden international has netted just twice in six appearances in all competitions for PSG so far this term and has been missing sharpness in front of goal, having recently returned from injury.
Maxwell has stressed that Ibrahimovic still has plenty to offer, though, and feels it is unfair to criticize the 33-year-old.
"For me it's funny to hear what everybody is saying about Ibrahimovic after all he has done in his career and even this season," he told reporters.
"He has been injured and is still lacking a bit of rhythm, but he has found his confidence and us scoring goals. He only needs to play some more games.
"It is ridiculous to criticise a player like Ibrahimovic now."
Ibrahimovic will be looking to add to his tally for 2015-16 when PSG take on Shakhtar Donetsk on Wednesday, but Maxwell has stressed Mircea Lucescu's men should not be underestimated.
"Shakhtar have some very strong attacking players," he added.
"We have made some mistakes, but we are satisfied with our season so far.
"This PSG is the most competitive team I have been part of, together with Barcelona." /End/