Manchester United manager Sir Alex Ferguson has issued a stark warning to clubs who are promoted to The Premiership.
With Reading already booking a place in next season's top flight, the Red Devils boss believes the secret is to get off to a good start.
He claims his theory has been supported by West Ham and Wigan Athletic's surprisingly impressive campaigns and Sunderland's dismal slide towards relegation.
"It's not easy coming out of the First Division into our Premiership," he informed Sky Sports News.
"It's a two-way street. You either go one way up the way or, if you don't get a good start, you go back the way like Sunderland. Unfortunately, they've experienced that very factor - if you don't get a good start, you're dead.
"West Ham and Wigan both had good starts and capitalised on those starts. When West Ham had a little blip, they had enough points to consolidate in mid-table, maybe just slightly below that, and the FA Cup run has galvanised them."
Ferguson is confident ahead of The Hammers' trip to Old Trafford on Wednesday night.
"We've got a nice cushion [for second place]," he said.
"We obviously have big games coming up.
"We've got to go to Chelsea, Bolton and Tottenham - three massive games away from home, and we have five at home, but the way we're playing, I don't think it really matters who we play.
"The team is playing with great confidence and authority and hopefully, like anything else, you hope you don't get any serious injuries to your main players."
With Reading already booking a place in next season's top flight, the Red Devils boss believes the secret is to get off to a good start.
He claims his theory has been supported by West Ham and Wigan Athletic's surprisingly impressive campaigns and Sunderland's dismal slide towards relegation.
"It's not easy coming out of the First Division into our Premiership," he informed Sky Sports News.
"It's a two-way street. You either go one way up the way or, if you don't get a good start, you go back the way like Sunderland. Unfortunately, they've experienced that very factor - if you don't get a good start, you're dead.
"West Ham and Wigan both had good starts and capitalised on those starts. When West Ham had a little blip, they had enough points to consolidate in mid-table, maybe just slightly below that, and the FA Cup run has galvanised them."
Ferguson is confident ahead of The Hammers' trip to Old Trafford on Wednesday night.
"We've got a nice cushion [for second place]," he said.
"We obviously have big games coming up.
"We've got to go to Chelsea, Bolton and Tottenham - three massive games away from home, and we have five at home, but the way we're playing, I don't think it really matters who we play.
"The team is playing with great confidence and authority and hopefully, like anything else, you hope you don't get any serious injuries to your main players."
