The Scarlets head coach said: "Leinster come to us with a strong 22. They have a powerful squad with quality overseas players so they'll be very competitive indeed this weekend.
"Given the space, time and opportunity, Leinster can be as good as any side - and I know they want to retain their Magners League title - so expect a tremendous effort from them at Parc y Scarlets."
Davies views this game as hugely important in the context of his team's season. He said: "A couple of months ago the coaches and players spoke in detail as a group about ensuring that, by mid-February, we'd be competing strongly for the league title. I'm glad to say that, with five home games - including Leinster - and three away trips to come, we're still very much in the chase.
"It's very important that we do well in this competition so it follows that it's important we do well in this weekend's game. At the top now, any team which puts together a run of wins can start to pull away - and that's what our squad is very focused
"We want to maintain the momentum we've had since Christmas. The boys have been working hard and they're eager to get back into action.
Scarlets (v Leinster, Feb 21) - 15 Morgan Stoddart, 14 Darren Daniel, 13 Regan King, 12 Jon Davies, 11 Matthew Jacobs, 10 Rhys Priestland, 9 Martin Roberts; 1 Iestyn Thomas, 2 Ken Owens, 3 Deacon Manu, 4 Lou Reed, 5 Dominic Day, 6 Vernon Cooper, 7 Simon Easterby (c), 8 David Lyons. Reps - 16 Phil John, 17 Mahonri Schwalger, 18 Josh Turnbull, 19 Rob McCusker, 20 Gavin Cattle, 21 Gavin Evans, 22 Ceiron Thomas.