New Blackburn Rovers manager Tony Mowbray
Keane scored nine goals in 10 games for the Bhoys under Mowbray, who was sacked less than two months after the Irishman's arrival in Glasgow.
Now the manager of Blackburn Rovers, could Mowbray forge a reunion with Keane seven years on?
The former Liverpool striker remains a free agent after leaving Los Angeles Galaxy late last year, and told Talksport in January that he is keen to continue playing despite his 37th birthday approaching.
With the Championship's third worst defence this season, Blackburn's priority between now and the end of the campaign - other than climbing out of the division's relegation places - is likely to be keeping goals out, especially with strike pair Danny Graham and Sam Gallagher both into double figures for goals scored.
But there is little doubt that signing a player of Keane's standing - having also played for Tottenham Hotspur, Leeds United and Internazionale as well as Celtic - would give everyone at Rovers a lift.
Celtic's Robbie Keane celebrates
The Dubliner could even replace another former Celtic goalscorer at Ewood Park, after Anthony Stokes was linked with a move to Poland on loan.
Could a Celtic reunion be on the cards at Blackburn Rovers?
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