Pepe has been one of Europe’s hot prospects this season and has been regularly linked with a move to the Emirates.
However Arsenal are likely to face competition from the likes of Bayern Munich and Paris Saint-Germain.
It’s believed Lille want around €50million (£43m) for the 23-year-old, and Lopez’s comments suggest clubs have already spoken to the Ligue 1 side over a possible transfer.
“It is certain, he will leave,” Lopez said.
“He has moved into a price range that we can not afford anymore.
“There is a career choice to make for him, I think he will have the choice.”
Arsenal boss Unai Emery could be limited when it comes to summer spending having been forced into only making loan deals during January.
And Arsenal hero Robert Pires knows his former side could have a problem if they want to sign Pepe.“Pepe would be a fantastic signing for Arsenal, but they’re going to have to pay big money to secure him,” he recently said.
“He’s building up a lot of interest as he’s playing so well and lots of clubs will be in for him this summer so I can’t see him going for cheap.
“These are the type of signings Arsenal need to make to propel them back up the table, but I think they will miss their chance if they don’t secure a Champions League spot this season.
“Pepe is a Champions League player and will want to play for a club that’s in the tournament.”Arsenal are back in action as they visit Watford on Monday night.
As well as Pepe, it’s been claimed that Arsenal are also mulling over a shock bid for Tottenham ace Toby Alderweireld.
Alderweireld’s contract expires next summer and a clause in his deal means the Belgian can leave this summer for just £25m.
And the Sun claim that Arsenal have stepped up their interest following a number of injuries.