Barler was on top form after his summer fitness regime but now joins Sam Miller on the long term injury list.
Andy Turner, who has been growing into big Sam's No 8 shirt, also picked up a knock and won't figure this week. However, Adam Brown, Scott Butcher and Michael Hogan are all back.
Butcher has been another bonus after his conversion from the wing to the back row where he's relishing the opportunity to actually get the ball in his hands.
He'll start in a team which more than held its own against the league leaders last week - despite a number of changes which meant we couldn't get a seocnd team out.
Jake Linighan is another youngster who gets better every week, as he eases his way into senior rugby. He will pack down alongside Hogan with the athletic John Bunter moving to the back row where Adam Brown is back from settling into Uni and will be looking to follow up his excellent try at Malton and Norton.
Morpeth, always strong on their own pitch, are in third place after starting the season with a draw at Alnwick followed by wins against Dinnington and Northern.
West: Luke Mallinson, Ben Armstrong, Peter Youll, Paul Moss, Will Hilditch, Zac Southern, Ryan Painter (capt), Ross Wood, Andrew Rollins, Alex Key, Michael Hogan, Jake Linighan, John Bunter, Scott Butcher, Adam Brown.
Changes: Craig Hadwen, Adam Peacock, Kyle Jamieson.
Morpeth: Jonny Ward, Sam Hornby, Alex Tait, James Phillips, Liam Allen, Fraser Boldy, Jack Elliott, Ben Sandall, Carl Hill (capt), Anthony Moody, Steve Long, Karl Campbell, Ian Burnham, Josh Williams, Matt Dawson.
Changes: James Armstrong, Blake Robinson, Chase Evans.