Roy Hodgson's side currently top Group H by a single point, and know only a maximum return on Friday and next Tuesday will be enough to guarantee progression to Brazil next summer.
|17/2||England are 17/2 with Paddy Power to come from behind to beat Montenegro
"Ukraine was a tough game, my biggest to date, but these next two games will be another step up in pressure, no question," Wilshere told Sky Sports News.
"It has not surprised me how hard the campaign has been. International football is tough.
"I know a few of the Poland players from Arsenal and they will not give up easily, Montenegro are the same. It is in our hands now, and we have to get ready for it."
England host Montenegro on Friday before Poland make the trip to Wembley on Tuesday.