The 6ft 4in Lewis, who made his Premier League debut at Hull 10 days ago, is set to start against the Hammers as David Marshall takes a breather.
"We're going to West Ham full of confidence and looking for the win," said Lewis. "It would be exciting to be involved in the tie.
"Being knocked out in the opening rounds of both the League Cup and FA Cup last season was hugely disappointing. That's an extra incentive to make sure we do well tonight."