The Belgium international is known to be on Arsene Wenger's wanted list, however the amount of cash it would take to secure the player could scupper Wenger's attempts to complete a deal.
The Gunners would have to pay £22million to Everton to activate the release clause in his contract and, with the player's wages, the total package involved could cost the Gunners £50million.
Wenger is reluctant to pay that kind of money and will check out alternative targets before making a final decision on the player, who is also said to be a target for Manchester City and Chelsea.
Meanwhile, Roberto Martinez is anxious to keep hold of the midfielder if he can.
Everton last week