The British filmmaker is currently shooting the first two episodes of Doctor Who's eighth series - the first to star Peter Capaldi as the Doctor.
Shearsmith - who worked with Wheatley on his 2013 effort A Field in England - told Digital Spy: "I think [Ben] thought it would be an exciting project to get his teeth into.
"He's learning all the time and I think he thought it would be a good challenge to do it. It's [also] very prestigious to do Capaldi's inaugural episodes."
Shearsmith added that Wheatley is not "setting out to put his stamp" on the BBC sci-fi drama, but simply "wants to do a good job of telling the story".
"I'm not sure that you could ever somehow visually taint it with your style," he suggested.
"Maybe it'd be different if he was writing it as well. There's a very abrupt and savage streak in Ben's work, but I don't think it will quite filter through... with a Who script."
Inside No 9 - a new darkly comic anthology series from Reece Shearsmith and Steve Pemberton - begins Wednesday, February 5 at 10pm on BBC Two.
Doctor Who, Peter Capaldi and series 8: Everything you need to know