Manchester United have reportedly agreed a world-record transfer fee with Juventus to bring the Frenchman back to Old Trafford this summer.
The Italian club have valued their star asset at over £100 million and a deal is said to be close to being officially announced.
Last week, Wenger said the money involved in signing the 23-year-old was “madness”.
“Football has become a global competition and that is why clubs are chucking these kinds of sums around.”
Klopp was questioned over the fee last month and insisted Man United’s investment “could all go through the chimney”.
“If you bring one player in for £100million or whatever, and he gets injured, then it all goes through the chimney.”
Mourinho confirmed United would be signing a “very good midfield player” on Friday and insisted comments from his fellow Premier League bosses were not ethical.
“I only speak about us,” Mourinho said.
“I heard already two of my colleagues from other clubs speaking about us. I do not like that. It is not ethical.
“There are things that when I do are not ethical and when others do it everything is normal, nobody says that. I do not speak about the others. They can do what they want. Our market was good.
“We made decisions, decide to bring four players not 10, that are Manchester United level. Four that we think can really improve the squad and not just be one more. This is the profile of our market.”
Mourinho has confirmed he wants to close Pogba’s deal before his side take on Bournemouth in the opening fixture of the Premier League on August 14.
It’s an exciting time for Man United supporters and Pogba’s deal could be one to take the club to the next level this season.