Watford boss Adrian Boothroyd today warned the promoted clubs to expect the toughest challenge in football in the Barclays Premiership next season.

Boothroyd's men will play in the Coca-Cola Championship in the 2007/08 campaign following their relegation this term, with Birmingham, Sunderland

and one team from Derby, Southampton, Wolves and West Brom trying their luck in the top flight.

Boothroyd conducted thorough research about life in the Premiership after his side's triumph in the play-offs last May - but he admitted the process

had been of little use.

"I sought advice. I made sure I spoke to people because I wanted to find out what it was like," Boothroyd said.

"I had a huge file's worth of information - but, in the end, you might as well just get someone to hit you over the head with it.

"It is like driving a car - until you have stalled a few times, you never really know what it is like.

"You just have to live it, and make sure you get the lessons out of it, because there are so many there to be had."

Boothroyd's team face Newcastle on Sunday in their final game of a hugely difficult campaign, which saw them win only five of their 37 league matches

so far.

He is already planning for an instant return next season, and has identified his principal transfer targets.

The 36-year-old Vicarage Road chief admits he might have adopted a different recruitment policy last summer.

He continued: "I tried to bring in some experienced Premiership players, who knew what the league was all about.

"I could perhaps have pushed harder to do that.

"I know what I will do differently next time we are promoted, but after we were promoted from the Championship there was a mixture of euphoria,

enthusiasm - and absolute panic.

"But I wouldn't have changed my squad around too much. Reading didn't, and they have been successful.

"The difference between them and us is that they have more experienced players, and had spent more time together as a squad before they were promoted.

"(Midfielders) Steve Sidwell and James Harper have been together for four-and-a-half years, and the back four and (goalkeeper) Marcus Hahnemann for a

similar length of time."

Boothroyd welcomes back defender Clarke Carlisle for tomorrow's match after the centre-back missed the 2-0 win at Reading last weekend through

suspension.

Carlisle is expected to replace young Frenchman Cedric Avinel, while goalkeeper Ben Foster plays his final game for the club before returning to Manchester United after a hugely successful two-year loan spell in Hertfordshire.

The 24-year-old has forced his way into the England squad during his time at Watford, and returns to Old Trafford as one of the best goalkeepers in the country.

Boothroyd hopes the success of Foster will persuade other top young players they can prosper at Vicarage Road.

He added: "I would point to Ben as proof that big clubs to send players on loan here, safe in the knowledge they will develop and get experience they might not get in a Premiership club's reserve team."