Zola who netted on Saturday against Brighton took a whack on his ankle and has not trained since.
Boss Steve Holland looks like he will pair Tom Pope and Anthony Elding up front tonight as the Railwaymen look to take a Championship scalp and progress to the next round of the League Cup.
Eugen Bopp is also ruled out after only lasting 16 minutes on Saturday with the Ukranian midfielder pulling an abductor muscle that will keep him out for at least two weeks.
With Bopp ruled out Holland must decide either to play Ben Rix who came on for Bopp on Saturday or play Byron Moore to add some pace and width on the right.