Irish international Kieran Marmion, who celebrated his 23rd birthday this week, has returned from camp to take his place at scrum half for his 65th Connacht appearance. Jack Carty starts at outhalf for the 15th time this season.
Darragh Leader shifts from wing to fullback with Niyi Adeolokun and Matt Healy starting on the wings in a back line with an average age of just under 24.
In the centre, this season's top try scorer Danie Poolman is named to start outside Dave McSharry who recently committed two more years to the province.
Up front, the front row is boosted by the return of tighthead prop Nathan White who plays his first PRO12 game since October.
Jake Heenan makes his long awaited return since his injury in round 1 of the competition and starts in a back row with captain John Muldoon and Number 8 George Naoupu.
From the bench Eoghan Masterson and Tiernan O'Halloran are in line to make their season debut while it would be a first cap for outhalf Shane O'Leary if he was called upon.
Commenting on the team selection and the upcoming game, Head Coach Pat Lam said:
"We lost Eoin (McKeon) and Mils (Muliaina)* to injury which was obviously a big blow especially on top of the loss of another back row in Willie (Faloon). But with these guys going down, it's good to welcome back Jake (Heenan) and Tiernan (O'Halloran) from long-term injuries.
"What we see with this team are the huge opportunities up for grabs for so many young players. The likes of Shane O'Leary, who has worked hard in training and for the Eagles, has his first match day involvement and we're delighted for him.
"This is a huge game for us against a well-coached and quality side in Scarlets. We know they are breathing right behind us and like us, they have top six aspirations. We haven't won on their soil since 2004 and we've never won at Parc y Scarlets. We've challenged ourselves to take it to another level for this block of four games, and it must start with a performance this Sunday."
*Eoin McKeon sustained a fractured sternum and is expected to be out of action for four weeks. Mils Muliaina is also looking at up to four weeks on the sidelines with a hamstring tear.
Connacht team to face Scarlets
15. Darragh Leader
14. Niyi Adeolokun
13. Danie Poolman
12. Dave McSharry
11. Matt Healy
10. Jack Carty
9. Kieran Marmion
1. Denis Buckley
2. Tom McCartney
3. Nathan White
4. Quinn Roux
5. Aly Muldowney
6. John Muldoon (captain)
7. Jake Heenan
8. George Naoupu
Replacements:
16. Dave Heffernan
17. JP Cooney
18. Rodney Ah You
19. Ultan Dillane
20. Eoghan Masterson
21. Ian Porter
22. Shane O'Leary
23. Tiernan O'Halloran
Unavailable/Injured: Jason Harris-Wright, Sean Henry, Michael Swift, Willie Faloon, Eoin McKeon, John Cooney, Craig Ronaldson, Bundee Aki, Robbie Henshaw, Mils Muliaina.
SCARLETS v CONNACHT
At Parc y Scarlets, 12.45pm
Live on SC4
Deferred on TG4
Referee: Marius Mitrea (FIR 36th competition game)
Assistant Referees: Wayne Davies, Martyn Lewis (both WRU)
Citing Commissioner: John Charles (WRU)
TMO: Tim Hayes (WRU)
Guinness PRO12
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