Treviso coach Kieran Crowley made only two changes to the starting line-up.
In the back-line Angelo Esposito and Luke McLean play on the wings with New Zealander Jayden Hayward at full-back. The centres conmsist of Tommaso Benvenuti and captain Alberto Sgarbi at 12. In the half-backs Giorgio Bronzini starts at nine who is joined by Thomas Allan, who was man of the match against the Dragons last week.
In the will see forward pack Alberto De Marchi replaces the injured Nicola Quaglio, while Simone Ferrari, is replaced by hooker Ornel Gega. In the second-row of Marco Fuser couples with Filo Paulo. And in the back-row flankers Francesco Minto and Dean Budd are at the side of the scrum with Abraham Steyn at number eight.
Meanwhile, Scarlets and Wales centre Scott Williams will make his 100th appearance in Scarlets colours on Saturday night.
25-year-old Williams returns to the starting line-up having come off the replacements bench in the last rounds rounds, against Ulster and Connacht respectively.
He lines up in midfield alongside Hadleigh Parkes, who made his 50th appearance last weekend.
Canadian international DTH van der Merwe makes a return from illness that has seen him sidelined for the last three games. His return to the wing sees international Liam Williams return to his preferred full-back position.
Gareth Davies, Rhys Patchell and Steff Evans retain their places at scrum-half, fly-half and wing respectively.
The pack sees the return of Wales tight-head prop Samson Lee, making his first appearance in Scarlets colours since the victory over Newport Gwent Dragons at Judgement Day IV in April. Rawlins comes in to the second-row alongside David Bulbring.
Scarlets head coach Wayne Pivac said: "It was a relief to get the first win [last weekend against Connacht]. Hopefully we've broken the shackles a little bit.
"We look forward now to backing that up on the weekend against Treviso. We've got to build on a slow start and make sure that we gather some momentum now.
"Treviso have improved on last year and they're a different side in terms of how they play their game.
"We've won our games in Italy in the past but we've won none of the comfortably, they've all been a struggle and a battle through the 80 minutes. I think one thing that hasn't changed is they're focused on their home games. They're a definite threat."
Form: Treviso beat Newport Gwent Dragons 27-11 at Stadio Monigo on Friday and have not won successive matches in the PRO12 since February. The Italians have won their last three home games against Welsh regions. Scarlets also won their first game of the 2016/17 campaign with a 17-8 victory at home to Connacht on Saturday. The Welshmen have slipped to three straight away defeats but have been victorious on their last five visits to Italy. Scarlets have won their last six encounters with Treviso since the Italian’s 41-17 victory at Parc y Scarlets in May 2013.
Treviso: 15 Jayden Hayward, 14 Angelo Esposito, 13 Tommaso Benvenuti, 12 Alberto Sgarbi(c), 11 Luke McLean, 10 Thomas Allan, 9 Giorgio Bronzini, 8 Abraham Steyn, 7 Dean Budd, 6 Francesco Minto, 5 Filo Paulo, 4 Marco Fuser, 3 Simone Ferrari, 2 Ornel Gega, 1 Alberto De Marchi.
Replacements: 16 Luke Bigi, 17 Matthew Zanusso, 18 Cherif Traore, 19 Filippo Gerosa, 20 Marco Lazzaroni , 21 Tito Tebaldi, 22 Ian McKinley, 23 Andrea Buondonno
Scarlets: 15 Liam Williams, 14 DTH van der Merwe, 13 Hadleigh Parkes, 12 Scott Williams, 11 Steff Evans, 10 Rhys Patchell, 9 Gareth Davies, 8 John Barclay. 7 James Davies, 6 Aaron Shingler, 5 David Bulbring, 4 Lewis Rawlins, 3 Samson Lee, 2 Ken Owens(c), 1 Wyn Jones,
Replacements: 16 Ryan Elias, 17 Luke Garrett, 18 Werner Kruger, 19 Rynier Bernardo, 20 Morgan Allen, 21 Aled Davies, 22 Aled Thomas, 23 Steff Hughes
Date: Saturday, 1 October
Venue: Stadio Monigo
Kick-off: 20:05 local (18:05 GMT)
Referee: Gary Conway (Ireland)
Assistant Referees: Nigel Correll (Ireland), Simone Boaretto (Italy)
TMO: Francesco Grillo (Italy)