Old Trafford (Manchester) will host the penultimate fourth Test of this series from 4th September.
Denly made six and 17 in his only previous outing as an opener, in Antigua this January, but showed his ability to focus and bat time by gritting out an important 50 in England's famous series-levelling win at Headingley.
England will hope that Denly can add some solidity with Rory Burns when the fourth Test gets underway at Old Trafford on Wednesday, as the latter's Surrey team-mate Roy has accumulated just 62 runs in the three Tests so far.
"I can confirm that, it's all true", Denly told BBC Sport.
"Obviously, Jason's going to bat at four". With Jason Roy in the team, we're a better team, that's for sure.
"With him coming in at four with hopefully the new ball worn off, and hopefully myself and (opener) Rory (Burns) doing our jobs at the top, it enables him to come in and play his way".
Ben Stokes' brilliant knock helped England to secure an impossible-looking victory in the last Test at Leeds.
"It's a great opportunity for him to make it his own and we have seen him play enough global cricket to know what he can do when he gets himself in, so hopefully batting lower down allows him to do that".
"It's all a bit of a blur.it's all about the last hour", he said.
England's one-wicket win at Headingley prevented Australia from retaining the Ashes, and Broad said this was the most closely-contested series he had been a part of.
"You saw him come into Ashes cricket on debut and straight away he looked very much at home and got himself in a battle".
"Thankfully, we had King Stokes to come in and finish it off".
"I don't think that's going to sink in for a while actually".
England batsman Alex Hales, meanwhile, has reasserted his commitment to one-day cricket by signing a two-year white-ball deal with Notts Outlaws.