Three thousand fans had descended on Nottingham hoping for some excitement in the world’s greatest knock out competition, but all they got was abject misery.
Nine changes were made, with only Stewart Downing and Modibo Maiga remaining from their defeat by Fulham on New Year’s Day and instead a team of youngsters, including three debutants in Danny Whitehead, Seb Lletget and Callum Driver, were included.
The game thus became little more than a Sunday stroll for Billy Davies’ side, with Jamie Paterson scoring a hat-trick and Republic of Ireland international Andy Reid also on target.
The magic of the cup? There was none here with Allardyce forced to defend his stance later and admitting he fears the sack if his side lose at Manchester City in the Capital One Cup on Wednesday and Cardiff City in the Premier League three days later.
“It might have repercussions for me, who knows? It’s the decision of people above me, not mine,” he said.
“I’m not saying it won’t happen unless I start to get results. I’ve got to get results, I know that.
“I made the board aware there would be changes today, I don’t go about my business without telling people internally what will happen in the next few games. “They understand I have to look at what’s happening for the next week and they were fine with me making the changes.
“You know what my priorities are. The priorities are the Premier League first and then Capital One Cup. It’s a disaster for me at the moment, my hands are tied as I see what’s available.”
Right from the first kick it was clear Forest would win as they set up a fourth round meeting at home to Ipswich or Preston.
Djamal Abdoun scored his first goal for the twice-European Cup winners when he converted a spot kick with a delicate chip after George Moncur, son of former Hammer John, had tripped Paterson on 12 minutes.
West Ham somehow stayed in the contest until the 65th-minute, even though Davies’ men missed chances.
The visiting defence could not handle the pace and drive of Paterson as he scored his first for the club, with a shot that beat Adrian after Greg Halford won the ball in the air.
A third followed on 71 minutes as Paterson finished following good play by Henri Lansbury and then he scored the hat-trick eight minutes later after confidently collecting Reid’s pass.
Republic of Ireland midfielder Reid had signed a new two and a half year contract before this game and celebrated by adding the fifth from close range in injury-time after Abdoun’s run created the chance.
“Someone was waiting to be hit for four or five,” said Davies. “But I feel for Sam, it would be a huge job for them to stay in the Premier League.”
NOTTM FOREST (4-5-1): Darlow 7; Jara 7, Lascelles 7, Hobbs 7, Lichaj 7 (Harding 58, 6); Abdoun 8, Moussi 7, Lansbury 7, Reid 8, Paterson 9 (Derbyshire 83, 6); Halford 6 (Cox 75, 6).
WEST HAM (3-4-3): Adrian 5; Driver 5, Diarra 6 (Burke 55, 5), Potts 5; Jarvis 5, Whitehead 5, Lletget 7, Downing 4 (Turgott 64, 5); Moncur 4 (Fanimo 55, 5), Morrison 7, Maiga 5.
Referee: M Atkinson 6.