Emery's comments came after Arsenal lost 2-1 to Lyon in a preseason match on Sunday, a match that saw Alexandre Lacazette come off with an ankle knock which Emery called "not serious."
The potential arrival of Pepe from Lille could provide a timely boost to Arsenal, with the goal-scoring winger tipped to complete a £72million (€80m) move.
Emery refused to confirm the validity of such reports, though he made no secret of Arsenal's admiration for the Ivory Coast international.
"The club is thinking on how we can improve," he said. "There are different players on the table.
"Pepe's a very good player. We only want players who can really, really improve the squad. We want the best players possible for the first game at Newcastle [on August 11]."