Steve Clarke believed lady-luck deserted Albion as the Baggies crashed out of the FA Cup.
After conceding in injury time in the first game against QPR, Albion found goalkeeper Robert Green in unbeatable form and conceded after Boaz Myhill's mistake.
“It is disappointing,” said Clarke.
“It’s a competition we wanted to stay in as long as possible.
“I think on the night we had the better chances and Rob Green made a few decent saves.
“We went to sleep on a set-play and you get punished for that at this level.
“We tried hard.
“The squad has been stretched in recent weeks and the boys that have gone in have done their best.
“They’ve tried hard, they’ve worked.
“Maybe the little bit of luck we were carrying a few weeks ago has deserted us a little bit.
“But all we can do is knuckle down and get on with it.”