George McCartney has warned his West Ham team-mates there is little room for error if they are to achieve automatic promotion.
The Hammers were beaten 1-0 at league leaders Southampton on Tuesday night - their first away defeat of the campaign - and the 30-year-old left-back admitted it is crucial they respond immediately when they travel to Brighton on Monday.
The Northern Ireland international told the club's official website: "Games like Tuesday you have to win if you want to win the league. You have to try to pull away from other teams. The longer you hang around third, fourth or fifth place, the harder it gets because games run out."
He added: "We have to put it behind us. We're all disappointed but we're all confident of finishing in first or second place come the end of the season.
"You try to go as long into the season not losing away from home or at home. We had good away form before Tuesday night so we'll get back on the training pitch and see where we went wrong."