The released Manchester United striker signed for the Potters last week.
Collymore wrote in the People: "Forget that he hasn't been involved in the international set-up for a while. He has scored World Cup goals against teams like Argentina, Germany and Brazil and we don't have anyone else like that. Rooney certainly hasn't done that.
"So if he gets a run of games at Stoke and is scoring goals every other game while avoiding injuries, I think you have got to include him.
"He could be such a valuable asset - and I'd even have him with the boys out in Brazil for the Finals if he's looking fit and sharp. He will be 34 by then, but so what?
"Many other nations do not worry about age and I wish we would adopt that same mentality."