Craig Morrison admits his side fell way below standards in their 4-2 loss to Glenrothes.
Glens were rarely troubled on their visit to Barnetts Park on Saturday and cruised to three points.
It was simply not good enough for United gaffer Morrison who now expects a positive reaction when they host Downfield this weekend.
“I was fuming,” said the manager.
“If I could have made 10 substitutions after 25 minutes then I would have.
“It was so disappointing and easily the worst performance since I took over.
“Training had been good during the week and the tempo was great but the guys have been massively complacent.
“I don’t know if us signing Jack Wilson from Kelty the night before has led them to think all they had to do was turn up, but it was a disgrace.”
Saints certainly turned heads with the signing of striker Wilson, brother of ‘keeper Lee, with a host of Super League sides also keen to grab his signature.
Morrison rates him highly, with Wilson deciding to make the move down a division after being impressed by the club’s vision for the next few seasons.
He’s likely to play a big part in this weekend’s game.
“The players didn’t see many footballs at training on Tuesday,” said Morrison.
“But there was no moaning about it and we had a good, positive chat about what went wrong afterwards.”