Tony Pulis was left disappointed after Albion's poor 1-0 defeat to lowly Norwich City.
The Baggies boss watched his players impress in traning in the week before a disjoined performance against the Canaries.
Albion started bright and Claudio Yacob rattled the crossbar before Stephane Sessegnon missed a one-on-one chance.
But Albion quickly ran out of ideas and conceeded to Robbie Brady's scrapy goal just after half time.
"It was very disappointing. It was a poor game," said Pulis.
"Apart from Sessegnon's shot we didn't do anything right, they didn't anything.
"I said at half-time that it was one of those games we need to grind out, keep a clean sheet...and then lo-and-behold they score.
"It was a poor, poor goal from our point of view.
"We've played so well in recent weeks - to put up a performance like that is very disappointing.
"The players had been bright all week but it goes to show: Monday to Friday means nothing. It's Saturday where it counts."
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