The Brazilian says that he never takes any joy out of the misfortune of a fellow professional, but confesses that the Argentine's absence will aid les Parisiens' cause
Messi is a major doubt for the second-leg showdown at Camp Nou having picked up a hamstring injury in last week's 2-2 draw at Parc des Princes, with the hosts expected to wait until the last minute before making a final decision on the Argentine's inclusion.
Maxwell insists that he does not wish any ill will towards his fellow South American but the defender is aware of just how big a blow his absence would be to the Blaugrana.
"Barcelona have a great squad but there is nobody that can substitute his level," the Brazilian told reporters on the eve of the game in Catalunya.
"I am not happy if anyone is injured, but it is a fact that Messi is a player that cannot be replaced."
However, PSG boss Carlo Ancelotti insists that his tactics will not be affected by whether Messi recovers in time to lead the Barca attack.
"We will play our own game," the former AC Milan coach declared. "We are going to have to use our qualities, be solid at the back, have patience and attack well."
Ancelotti, meanwhile, has his own injury concerns, with Thiago Silva and Thiago Motta both facing late fitness tests.
"With respect to Thiago Silva we need to wait and see the final training session," the Italian explained. "If there are guarantees he is fit, he will play.
"The decision on whether Motta will play will be taken at the last minute. The season doesn't finish tomorrow and there are more games to consider."
Ancelotti added that David Beckham could again start in midfield - even though the former England captain's contribution to the first leg was the subject of much debate in the French press.
"Some criticised him and some were happy with him," the tactician mused. "But it doesn't matter because I was happy with Beckham and thought he played a good game."
PSG's eagerly-awaited clash with Barcelona is set to kick off at 20:45CET.