Half-back Rangi Chase, centre Jack Reed and loose forward Chris Heighington all keep their places after making their debuts in England's 32-18 win over France in Avignon last Friday.
"It is an opportunity for that group of players to rectify some of the errors we made in the game against France and bring in some consistency," said McNamara.
England team to play Wales in Saturday's Gillette Four Nations Series match at Leigh:
S Tomkins (Wigan); R Hall (Leeds), J Reed (Brisbane), K Yeaman (Hull), T Briscoe (Hull); K Sinfield (Leeds), R Chase (Castleford); J Graham (St Helens), J Roby (St Helens), J Peacock (Leeds, captain), G Ellis (Wests Tigers), B Westwood (Warrington), C Heighington (Wests Tigers).
Substitutes: G Widdop (Melbourne), A Morley (Warrington), J Jones-Buchanan (Leeds), J Wilkin (St Helens).