West Ham boss Sam Allardyce has vowed to take the club up to the Premier League after missing out on automatic promotion.
Two goals from Carlton Cole at home to Hull City in a 2-1 win were not enough to overhaul Southampton, whose thumping victory against Coventry ensured they held onto second spot in the Championship.
Instead, the play-offs beckon for Allardyce and his side, who will face Cardiff in the first leg on Thursday before being back at home for the second leg a week on Monday.
And it is their home form which has proved costly - West Ham have won a club record 13 games on the road but dropped 28 points on their own turf to slip out of the top two.
Allardyce said: "I stuck my neck out when I arrived and said we wanted promotion in the first season.
"I've got a two-year contract but doing it in the first season is important. We still have three games to win, and we will do it.
"We've had a very good season considering where we've come from. In the last few years 86 points has been enough.
"Our ultimate goal was not achieved, we left ourselves too much to do, but we'll wake up tomorrow morning and look forward to preparing for the play-offs.
"We have to lick our wounds, get over our disappointment and get ready for the vital games ahead of us."
Hull pulled one back through Corry Evans, who took advantage of Guy Demel's poor header to nod the ball past Rob Green.
And the visitors thought they had equalised when Richard Garcia powered in a late header only to be flagged offside.
The Tigers' own play-off hopes ended a few weeks ago but manager Nicky Barmby feels they can go one better next season.
"There's a bit of frustration," he admitted. "I genuinely believed we could make the play-offs but we fell short.
"But the players are growing and getting better. I'm pleased with the lads overall and we'll be better for it next season.
"Will West Ham go up? It's hard to say, there are some good teams in the play-offs so it will be interesting."