Scarlets head coach Wayne Pivac has made four changes, one positional, to his starting XV for Saturday's clash at Treviso.
John Barclay remains as captain but moves to his more preferred position of openside flanker with James Davies sidelined with a foot injury.
Morgan Allen comes in at number eight looking to make his first competitive start for the Scarlets as he makes a return from a bicep injury suffered ahead of the opening round of the PRO12 campaign.
Jake Ball makes a return to the second row with Maselino Paulino moving to the replacements bench. Michael Tagicakibau returns to the wing in the only change to the backline.
Speaking earlier this week Pivac said: "They will be a very similar threat to Zebre who drove all of their line outs. Treviso are no different and they like to put pressure on through their forwards.
"It will be another tough ask away from home but we're looking forward to the challenge. It's a really important game.
"It's a tricky one this game, it's a must win for us to remain where we are and stay in the race really.”
Meanwhile, Treviso have made three changes, including a positional switch, to their team that lost narrowly to Glasgow last weekend.
In the only change to the backline, Edoardo Gori comes in on the left wing where he replaces Simone Ragusi.
Up front, there are two changes to the back row. Dean Budd takes over from Abraham Steyn at number eight while Alessandro Zanni comes in to the run-on side at openside flanker.
Zanni replaces Francesco Minto, who moves to the blindside flank at the expense of Marco Barbini.
Form: Treviso slipped to a 15 successive PRO12 defeat in Glasgow on Friday but at least picked up a fifth losing bonus point this campaign. Scarlets have lost just one of their last dozen PRO12 fixtures: 15-19 at Leinster in Round Seven. The Scarlets face Italian opposition for the second week running and have not lost to an opponent from that country since Treviso visited Parc y Scarlets in May 2013. The two sides have met on ten previous occasions in the PRO12 with Treviso gaining four victories to the Scarlets six. The Welshmen have won on their last two visits to Stadio Monigo.
Treviso: 15 Luke McLean (c), 14 Andrea Pratichetti, 13 Tommaso Iannone, 12 Sam Christie, 11 Edoardo Gori, 10 Jayden Hayward, 9 Chris Smylie, 8 Dean Budd, 7 Alessandro Zanni (c), 6 Francesco Minto, 5 Jeff Montauriol, 4 Teofilo Paulo, 3 Filippo Filippetto, 2 Ornel Gega, 1 Matteo Zanusso.
Replacements: 16 Roberto Santamaria, 17 Alberto De Marchi, 18 Simone Ferrari, 19 Tom Palmer, 20 Marco Barbini, 21 James Ambrosini, 22 Enrico Bacchin, 23 Simone Ragusi
Scarlets: 15 Steff Evans, 14 Michael Tagicakibau, 13 Regan King, 12 Hadleigh Parkes, 11 DTH van der Merwe, 10 Aled Thomas, 9 Aled Davies, 8 Morgan Allen, 7 John Barclay (c), 6 Aaron Shingler, 5 Lewis Rawlins, 4 Jake Ball, 3 Samson Lee, 2 Emyr Phillips, 1 Rob Evans.
Replacements: 16 Kirby Myhill, 17 Dylan Evans, 18 Rhodri Jones, 19 Tom Price, 20 Maselino Paulino, 21 Rhodri Williams, 22 Steve Shingler, 23 Gareth Owen.
Date: Saturday, December 5
Venue: Stadio Monigo
Kick-off: 15:00 (local) 14:00 GMT
Referee: Dudley Phillips (Ireland)
Assistant Referees: Giuseppe Vivarinni (Italy), Simone Boaretto (Italy)
TMO: Carlo Damasco (italy)