Stephen Jones is yet to figure for the Scarlets this season due to an ankle injury.
The Scarlets team has been announced as the squad prepare for their first Welsh derby of the season at the Cardiff City Stadium this weekend.
The starting XV against the Blues shows one change from last weekend's line-up at home to Munster with Richie Pugh comeing in at flanker for the injured Dafydd Jones (knee).
From the bench there could be first competitive Scarlets action for exciting young half-back pairing Tavis Knoyle and Dan Newton while Lions hooker,Matthew Rees is also on the bench.
Scarlets head coach Nigel Davies said the clash against the Blues would be an intense affair. He said: "If we look back to last season, the Blues didn't have the strongest of starts and people were writing them off after the first three weeks. But we all saw what they were able to do after that.
"Form doesn't count for much in these types of encounters - particularly Welsh derbies like this one, the first of the season. We have only won one game ourselves, it's going to be pretty intense stuff - it will be about desire and I am sure the Blues are going to be desperate for a win."
The Scarlets have performed well against the Blues in recent years and did the double last season. The teams have met 12 times since the advent of regional rugby, with the Scarlets winning eight and losing four.
For Saturday's game, Davies has opted to rest Lions fly-half Stephen Jones as a precaution to protect a minor ankle injury picked up in the past week and will rest Rhys Thomas following a cut to his knee which needed stitches this week.
Acknowledging Jones as one of the top stand-offs in the world, Davies said the Scarlets have erred on the side of caution this weekend. He said: "Their welfare is paramount, because there are key stages in the season where you want your top players firing on all cylinders.
"Obviously, the Magners League is important to us as it's a hugely competitive competition but we'll still look to peak in the European competition and that has been our primary focus.
"It's great to have the experience of Matthew to call on this weekend; he's been working well with us for the past three weeks now."
Coach Davies said the contest between Jamie Roberts and rising Wales and Scarlets star Jonathan Davies would be one to watch. He said: "Jamie Roberts will pose a big threat; it'll be a really interesting battle between him and Jonathan Davies. That's something I'm looking forward to and I'm sure everybody else is too.
"There are similarities in many ways. Jamie has done exceptionally well, he's huge and he has the ability to take the ball up and off-load through the tackle. Jon has a few strengths of his own and I think that'll make for a great contest on Saturday."
Scarlets: 15 Daniel Evans, 14 Sean Lamont, 13 Gareth Maule, 12 Jonathan Davies, 11 Mark Jones (c), 10 Rhys Priestland, 9 Martin Roberts, 1 Iestyn Thomas, 2 Ken Owens, 3 Deacon Manu, 4 Lou Reed, 5 Dominic Day, 6 Simon Easterby, 7 Richie Pugh, 8 David Lyons. Reps - 16 Phil John, 17 Matthew Rees, 18 Vernon Cooper, 19 Josh Turnbull, 20 Tavis Knoyle, 21 Dan Newton, 22 Lee Williams
Angus O'Brien has quickly settled into the Wales Sevens squad after solid performances in Hong Kong and Japan. With two rounds remaining in Glasgow and Twickenham on the World Series, WRU TV's Graeme Gillespie chats to the rising star.
Wales winger Luke Morgan has established himself as one of the deadliest finishers on the Sevens World Series. WRU TV's Graeme Gillespie catches up with him on the eve of this weekend's round in Glasgow.
All roads lead to Cardiff on Sunday for the SSE SWALEC Finals Day at the Millennium Stadium. Cambrian Welfare tackle Ystradgynlais in the Bowl final, Ystrad Rhondda play Newcastle Emlyn in the Plate final while defending champions Pontypridd face Bridgend in the Cup final.
WRU Chief Executive Roger Lewis, Deputy Minister for Culture, Sport and Tourism Ken Skates and WRU Chairman Gareth Davies earlier this week launched a new competition in conjunction with the WRU unveiling its archive room.
Welsh players and management joined Deputy Minister for Sport Ken Skates at the Pierhead Building, Cardiff Bay earlier this week to reveal the Union's pioneering school-club hub initiative has been so successful the project will now almost double the scale of the original project.
The Scarlets, Newport Gwent Dragons, Cardiff Blues and the Ospreys look ahead to Judgement Day III which sees the Blues take on the Ospreys (2.30) and the Dragons tackle the Scarlets (4.45pm) at the Millennium Stadium tomorrow afternoon.
Ystradgynlais and Ynysddu played out a titanic struggle at Taffs Well in the SSE SWALEC Bowl semi-final. At the end of the game neither team could be separated after a 15-15 stalemate but Ystradgynlais go through on try count.
Blues strike first in JD III battle - Newport Gwent Dragons lock Andrew Coombs, WRU referee Dylan Llyr Jones and Cardiff Blues hooker Matthew Rees decide dressing room allocations for Judgement Day III
Wales Under 18 captain Calum Haggett has received a conditional offer to read Biomedical Science at St Anne's College, Oxford. WRU chairman Gareth Davies went to meet Calum and Coleg y Cymoedd Principal Judith Evans to wish him luck in his exams and pass on some of his personal experience.