The Cork youngster, who turned 22 recently, was in the province's matchday squad for the league game against Leinster and the two recent Heineken Cup matches. He comes in, this week, for the benched Paul Warwick.
Other than Deasy's promotion to the starting line-up, Munster coach Tony McGahan has named a largely unchanged squad from the one that saw off Toulon last weekend.
The noticeable exceptions being Marcus Horan, who has been ruled out by a wrist injury, stand-in captain Denis Leamy, who has earned a break having played in six of Munster's seven games to date, and Niall Ronan, who has been equally as busy.
Leamy's place at number 8 goes to James Coughlan, a late try scorer as a replacement in the 45-18 victory over Toulon.
There are two other changes in the pack, John Hayes replacing Tony Buckley at tighthead prop and Donncha O'Callaghan making way for Donnacha Ryan in the second row.
Former UCC captain Ivan Dineen is poised to make his senior debut for Munster as a replacement. He played for the 'A' team in their British & Irish Cup opener against Llanelli last Friday.
Munster team manager Shaun Payne said: "The arrival of the Italian teams has added a lot of spice to the Magners League. Aironi, in the first game, gave us a bit of a scare and Treviso are a very good side.
"Their strength has been that they play as a team, with very good physicality, good work ethic, good set piece so it's not so much a team of stars but a proper team from 1 to 15."
MUNSTER (v Benetton Treviso): Scott Deasy; Doug Howlett, Keith Earls, Johne Murphy, Denis Hurley; Ronan O'Gara, Peter Stringer; Wian du Preez, Damien Varley, John Hayes, Mick O'Driscoll, Donnacha Ryan, Alan Quinlan, David Wallace, James Coughlan.
Replacements: Mike Sherry, Darragh Hurley, Tony Buckley, Donncha O'Callaghan, Peter O'Mahony, Duncan Williams, Paul Warwick, Ivan Dineen.