Allardyce now wants his players to rediscover the type of form that saw them win four games in a row back in February.
"We've put ourselves in a little bit of danger again, there's no doubt about that. In the two games we've got coming up we've got to make sure we perform like we did when we hit our good spell when we won four games on the trot," he told the club's official website.
"We've got to make sure we get back to, one, resilient defensive work which we didn't show enough of on Saturday to keep a talented frontline at bay, and two, we have to get better in the final third at creating and hurting teams. We didn't turn any of our opportunities today into goal scoring opportunities."
West Ham continue their Premier League campaign on Wednesday at home to Hull City.