Bedford's narrow win over Llanelli in round 2 - their first victory of the season - puts them level on points with the Scarlets.
The improving Blues will go into the game in buoyant mood after becoming the first side to beat London Welsh in the Championship this season. But Connacht Eagles will take confidence from their 27-25 win over Rotherham Titans in the last round.
Kick-off at the Sportsground is 2.30pm and there is free entry for all.
CONNACHT EAGLES (v Bedford Blues): Shane Layden; David Panter, Conor Finn, Brian Murphy, Steve Macauley; Jack Carty (capt), Paul O'Donohoe; Finlay Bealham, James Rael, JP Cooney, David Nolan, Daniel Qualter, Andrew Browne, James Connolly, Eoghan Masterson.
Replacements: David Heffernan, Peter Reilly, Ultan Dillane, Conor Kindregan, Sean O'Brien, Caolin Blade, Tadhg Leader.