The dynamic 21-year-old Northampton forward has seven caps from the bench and will start at No.8, with Tom Curry coming in at blindside flanker. Ben Earl moves to openside in a highly mobile back row.
Ollie Lawrence starts at outside centre with Tommy Freeman moving to the right wing in place of Tom Roebuck. Henry Arundell keeps his place on the left wing after being cleared to play following his red card in the 31-20 Murrayfield defeat that ended England's 12-game winning run.
Captain Maro Itoje will win his 100th cap, becoming the ninth England player to reach that milestone.
At the opposite end of the "on-field" persona is Pollock.
"He's a young man who is full of energy, full of character, full of beans all the time and he's already achieved so much in a very short space of time," Borthwick said.
"This is his second Six Nations, he's been on a Lions tour and each new level you challenge him with, he seems to thrive."
Borthwick said he was struck by Pollock's personality when he met him as an 18-year-old.
"I was stood in the car park and this bundle of energy just bounced up to me and, typically when an 18-year-old meets the England head coach for the first time they are usually on the shy and retiring side. But this man is the complete opposite, gregarious, loud, the first thing he said was, 'how are you, mate?'.
"I thought, 'right, you're different, wonderfully different' and that's the kind of character we've got in the squad."
ENGLAND v Ireland:
Steward; Freeman, Lawrence, Dingwall, Arundell; Ford, Mitchell; Genge, Cowan-Dickie, Heyes, Itoje, Chessum, T Curry, Earl, Pollock
Replacements: George, Rodd, Davison, Coles, Pepper, Underhill, Van Poortvliet, M Smith
