Gala Fairydean Rovers:
Goals from Mackenzie Carse (2), Corey Thomson and Rocco Vata (2) condemned the Borders outfit to a heavy loss which leaves them 10th in the table on four points from four games.
“Quite clearly Celtic B are the best side we’ve played this season,” Galbraith said. “But we’re only four games in.
"They played really well and we weren’t at our best. Probably that’s why we ended up with the scoreline that we did.
"We got our press wrong. We were stuck between a rock and a hard place at times.
"We showed last season in the games we played how to combat their strengths. To do that everybody needs to know their job and to carry it out near perfectly.
"We didn’t really do that. Defensively we probably didn’t carry out the instructions the manager gave us before the game.
"Obviously there's been a lot of personnel changes etcetera and there’s lots of things we need to work on.
"It’s fine losing to Celtic B and Rangers B, as it was last year, as that can happen against full-time players.
"In the previous games we've had against the Old Firm and Hearts B we have done really well at times but on Saturday we never got it right.
"When you don’t get it right against these sort of teams they can pick you off.
"Off the ball you need to do your job and you need to make sure that you’re 100% concentrated for the full game because anything less than that and they’re good enough players to hurt you and that’s what happened.
"But when you probably don’t do yourself justice it can be frustrating.”
In a break from league action, Gala Fairydean Rovers continued their campaign on Tuesday night with a 5-1 home victory against Glenrothes in the East of Scotland Qualifying Cup second round.
Despite going 1-0 down to a ninth-minute strike by Glens’ Conor Schiavone, Rovers comfortably progressed to round three thanks to goals by Jamie Semple, Nicky Reid, Kyle Semple, Sam Ostle and Lasana Drammeh.