The Blackburn manager admits that signing a new centre-forward is his priority following the £17 million sale of Roque Santa Cruz to Manchester City and Van Nistelrooy has emerged as a leading target with concerns over Michael Owen's fitness ruling out a move for the Newcastle forward.
Van Nistelrooy, who scored 150 goals in 219 appearances for Manchester United before completing a £12 million transfer to Madrid in 2006, has been made available by Real following the Spanish club's £135 million double move for Kaka and Cristiano Ronaldo.
Tottenham manager Harry Redknapp is also keen to sign the Dutchman, who will be 33 next Wednesday and is now fully fit following a cruciate knee ligament injury suffered last November.
But having enjoyed success at Bolton Wanderers by attracting box-office names such as Youri Djorkaeff, Jay Jay Okocha and Nicolas Anelka to the Reebok, Allardyce is now ready to pursue Van Nistelrooy, who would cost in the region of £1.5 million.
Allardyce said: "The sort of salary that Ruud would be on at Real Madrid may be beyond us, but if he wants to play in England again and take less of a salary, then we'd be interested.
"There's no doubt it would be of interest to me and I would want to talk to him. It would be a major coup if I could pull it off.
"I did that a few years ago with Nicolas Anelka at Bolton. His goals took us up to the next level, but it's what it did to the rest of the players as well as what he did on the pitch.
"Who'd have thought Bolton would get Nicolas Anelka? Nobody did, but I went out and did it. It was the same with Okocha, Djorkaeff and Fernando Hierro and it would be nice to do it with a Van Nistelrooy figure at Blackburn."
Allardyce has a transfer fund of £13 million after raising £20 million with the sales of Santa Cruz and Matt Derbyshire, but he admits that signing former England forward Owen would be too great a risk.
He said: "Michael is an exceptionally good player, but I just question the injury scenario. If he picked up the injuries he did at Newcastle, I couldn't afford that.
"I need a striker who is going to be available for 30 games next season. That's not happened for Michael over the last four years at Newcastle."
Van Nistelrooy, who scored 150 goals in 219 appearances for Manchester United before completing a £12 million transfer to Madrid in 2006, has been made available by Real following the Spanish club's £135 million double move for Kaka and Cristiano Ronaldo.
Tottenham manager Harry Redknapp is also keen to sign the Dutchman, who will be 33 next Wednesday and is now fully fit following a cruciate knee ligament injury suffered last November.
But having enjoyed success at Bolton Wanderers by attracting box-office names such as Youri Djorkaeff, Jay Jay Okocha and Nicolas Anelka to the Reebok, Allardyce is now ready to pursue Van Nistelrooy, who would cost in the region of £1.5 million.
Allardyce said: "The sort of salary that Ruud would be on at Real Madrid may be beyond us, but if he wants to play in England again and take less of a salary, then we'd be interested.
"There's no doubt it would be of interest to me and I would want to talk to him. It would be a major coup if I could pull it off.
"I did that a few years ago with Nicolas Anelka at Bolton. His goals took us up to the next level, but it's what it did to the rest of the players as well as what he did on the pitch.
"Who'd have thought Bolton would get Nicolas Anelka? Nobody did, but I went out and did it. It was the same with Okocha, Djorkaeff and Fernando Hierro and it would be nice to do it with a Van Nistelrooy figure at Blackburn."
Allardyce has a transfer fund of £13 million after raising £20 million with the sales of Santa Cruz and Matt Derbyshire, but he admits that signing former England forward Owen would be too great a risk.
He said: "Michael is an exceptionally good player, but I just question the injury scenario. If he picked up the injuries he did at Newcastle, I couldn't afford that.
"I need a striker who is going to be available for 30 games next season. That's not happened for Michael over the last four years at Newcastle."
