East takes on west in the regional RaboDirect Pro12 double-header in the capital.
- Last year the Scarlets and Ospreys were triumphant and both are favourites to take the spoils again.
- The Scarlets are hunting a win that will put them closer to securing the final qualification spot for next year's Rugby Champions Cup.
- The Ospreys need five points to keep the heat on Glasgow and Ulster in the battle for the playoffs.
- The Dragons are looking to end a run of five games without a victory that has seen them slide to 10th in the table.
- The resurgent Blues bid for a hat-trick of wins following their successes against Ulster and Edinburgh.