Scot has a chequered record as a manager and, despite Blackburn being on a downward curve before he was prised away to Newcastle in 2004, he has retained support on the club's board.
He is fondly remembered for taking the club back into the Premier League in 2001 and winning the Worthington Cup in the first season with young players Damien Duff, David Dunn and Matt Jansen. It is now considered a successful period.
Souness has been out of work since he left Newcastle 2½ years ago and was linked with an attempt to take over Wolves. If he returned, he would probably bring in his former coach Dean Saunders, who is manager of the Conference club Wrexham, to Ewood Park as well as work closely with Tugay, a player who he brought to the club in 2001.
The bookies' favourite and is seen as a steady pair of hands. He would relish reorganising and adding to a squad that has potential. Allardyce carved out a reputation at Bolton for making meagre transfer resources go a long way and he was even touted for the England manager's role when Sven Goran Eriksson stepped down.
Having admitted he would like the Sunderland job, Allardyce is unlikely to make too obvious any interest in the Blackburn post.
Cardiff's Dave Jones has a good track record in the top flight and Burnley's Owen Coyle is seen as a bright young manager and the former Inter Milan coach Roberto Mancini is looking for work in England, while Steve McClaren, Alan Shearer and Alan Curbishley are long shots.