The Hammers' manager hailed his team's home form, but was critical of their performances away from Upton Park, stating that they need to improve massively after just two away wins
The Hammers' boss can't quite put his finger on the reasons behind their poor away record, having seen his team play some great football at their Upton Park home, but it is something he is keen to put right ahead of Wednesday's FA Cup third round replay against Manchester United at Old Trafford.
"They can play but it's away from home that is becoming a bit of a concern for me because of the lack of performances and goals we're getting," he told West Ham's TV channel.
"It's becoming a big concern for me and I have got to make sure I put it right for Wednesday because otherwise we'll be looking at a real thrashing at Old Trafford and that won't be good for confidence going into the home game with QPR next weekend," he continued.
"Our home form and performances are outstanding but our away performances are the reverse of that - they are just not good enough."
West Ham started the season well, but just two wins in their last 10 games has put them in the bottom half of the table, and Allardyce has called for a big response from his players after a poor 3-0 defeat away to Sunderland on Saturday.
"We didn't look like the same set of players this week who played last week, with no disrespect to Sunderland because they are not as good as Manchester United, and managed to close Manchester United down and nearly shut them out," he said.
"We couldn't shut Sunderland out today, in fact we let them do what they wanted, attack when they wanted and play to their strengths when they wanted. Whenever they attacked and got around our box they looked like they were going to score," he continued.
"We showed no organisation or desire to stop them doing what they wanted to do, and we did all of that perfectly well against Manchester United, so it baffles me that the application to stop the opposition playing at home and to get the fans excited wasn't there.
"On the back of that, we're unlikely to go and win a game. We've got to win the right to play and stop the opposition when we're playing on their patch and then we can look to play from there on. We never did that [against Sunderland] at all."
The Hammers' boss is also concerned with his current injury list, with key players James Collins, Joey O'Brien and George McCartney all out, and will look to bolster his squad before the transfer window closes.
"Losing James is a massive blow. With Joey not here and George out with a long-standing medial knee ligament injury, to lose Ginge [Collins] to a tear in his calf leaves us threadbare defensively and I need to get somebody in as quickly as I can", he said.
"We need either a centre-back or a left-back, at least one of them, by the time we play QPR. We have to look very carefully at who we play on Wednesday and then for the following Saturday."