Roberto Martinez’s side recovered from 2-0 down to consign the Hammers to the Championship, thanks to a brace from Charles N’Zogbia and Conor Sammon’s first goal for the club.
The Latics still remain in the bottom three on goal difference but Whelan feels the result against West Ham can give them the belief to secure safety against Stoke.
"The squad are feeling fantastic," he told Sky Sports News.
"After the result on Sunday they were sky high and up for everything.
"The mood in the camp is really, really good and the way we have played in the last two months I think it gives everyone hope that we can go to Stoke and either get a point or get three.”
With five clubs battling to avoid joining West Ham in the Championship next season, the final day is sure to see supporters nervously checking on results elsewhere, but Whelan is excited for the occasion.
"It is going to be an awesome day," he added.
"We had this before at Sheffield United four or five years ago and we had to go there and win so we have to go to Stoke and win.
"If we get a point we could stay up, it is all boiling up and it is going to be one wonderful Sunday."