The 54-year-old was unveiled at a press conference at Ewood Park on Thursday, having rejected the chance to manage the Barclays Premier League club earlier this year.

He told the press conference: "Six months ago it was a case of speaking with (chairman) John Williams, going home and talking to my better half. After 15 years straight managing and coaching I decided it was too early to jump back into the mainstream.

Rovers are second bottom of the top flight with 13 points and Allardyce continued: "It's difficult - an unexpected position I think.

"Everyone here didn't expect the club to be in the position it is. But I've been there before and now the players must respond very quickly.

"You can never say you are too good to go down - clubs have fallen foul of that before - but the players have to play to the maximum of their ability to get us out of trouble, hopefully as quickly as possible."

Williams told the press conference Allardyce was "first choice and a unanimous candidate" to replace Ince with Rovers acting swiftly because of their perilous plight. 

The chairman explained: "It wasn't the classic interview situation as it was in the summer.

"The reality is we've now got 13 points and when Paul Ince left, the decision by the board was unanimous and quick.

"Experience is the word, he's been there (and) done it. There's a huge amount of confidence from the board down to the training ground - we feel we've got the man to pull us round."

Allardyce, who has also managed Newcastle United, will assess the players at his disposal before making any decisions ahead of the January transfer window.

He said: "I've got to evaluate the squad before even venturing into what we might or might not do in January.

"We don't want to have to sell anybody in the January transfer window.

"I know how good the players are so why would I want to sell the best ones? Why would I want to do that?"

Williams insisted he would back Allardyce with funds for transfers, adding: "We'll do our best - but he has already hinted the key is assessing what he's got.

"There's a general feeling we're perhaps underachieving and should be higher in the league but we'll do our best to support him.

"We always have done that with our managers, we've usually managed to give them every penny we have got - and some that we haven't got."

Allardyce appointed Neil McDonald as his number two and is planning "maybe one more addition".

He explained at the press conference: "I know quite a lot of the staff here and we'll roll along with that for now.

"It seems very professional, just a bit of tweaking is needed."

Allardyce was named Blackburn manager barely 24 hours after Ince was sacked only 17 matches into the season.

Having had his own spell at Newcastle cut short only a few months into last season, Allardyce acknowledges that the pressures of life in the Barclays Premier League have grown - but insists he is up for the challenge.

He added: "I've got a real good buzz about the place, so I'm pleased that I'm getting back to doing what I love the most," he said.

"As hard as it is sometimes as times goes on, you begin to get itchy feet; Saturdays come around and you go and watch as a neutral and you don't get the adrenaline rush that you're used to."

With Blackburn five points adrift of safety in 19th place, Allardyce knows there will be pressure from day one.

"It's certainly not easy," he said. "I hope the players will repeat the form that they've shown in the past. I'm hoping this is a blip, that this is a poor run of form they can overcome with my guidance.

"They've proven with their track record over the years that they are very good players and very experienced players."