Rovers chief Steve Kean confirmed over the weekend that the club are interested in taking the 34-year-old former Dutch international hitman back to the Premier League, following his successful spell at Manchester United earlier in his career.
Van Nistelrooy would also fit the bill for Blackburn's owners Venky's, who have been searching for a world star to come into the club, having already missed out on attempts to sign Ronaldinho and David Beckham in January.
The former Real Madrid star has revealed that he will not be signing a new deal with German Bundesliga outfit Hamburg, when his current contract expires this summer, and it has been reported that he would favour a move back to the Premier League or Spain.
Van Nistelrooy's reported £80,000-a-week wages could be an obstacle, while it is being suggested that Harry Redknapp could join the race for his services. And, if the Londoners manage to secure a place in Europe for next season via their Premier League finish, that would no doubt put them in the driving seat to sign the player ahead of Rovers.