The Gunners broke their transfer record in signing the 24-year-old last summer but the Ivory Coast international is yet to take the Premier League by storm, scoring just four goals and providing six assists in 24 league games.
Arteta – who helped oversee much of Raheem Sterling‘s development while at Manchester City – has previously insisted that Pepe remains a work in progress, vowing to help the winger individually in training.
Aliadiere admits he cannot deny Pepe’s talent, but states the forward must do more to justify his price tag.
“I saw what he did with Lille last season and he is an amazing player,” Aliadiere told Goal. “So, I’m not denying his talent.
“What I’m seeing, though, is the most expensive player in Arsenal’s history and even if you don’t want to think about the money, the fact is that money is, unfortunately, a big thing in football.
“And when you spend that much money on a player, you expect more goals and you expect more assists.”
He added: “You can see he has unbelievable potential, talent and quality. Technically, he can do incredible stuff, but the simple things, sometimes he doesn’t do them spot on.
“That’s why I feel maybe we shouldn’t have spent that much on him.”