Pepe arrived in a £72million move from Lille last summer and has six goals and eight assists in 32 appearances in all competitions.
“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."