After winning nine league titles on the trot, the Hoops ultimately lost their stranglehold over the Scottish Premiership when Rangers beat them to the title after amassing a 20-point lead at the top of the table.
Celtic have been without a permanent manager since Neil Lennon left the Hoops in February after falling 18 points below Rangers at the summit of the Scottish Premiership.
Keane finished his illustrious playing career at Celtic after a 12-year stint at Manchester United that saw him win numerous accolades.
The Irishman’s last stint as manager ended in 2011 when he resigned as Ipswich boss before taking the assistant manager role with the Ireland national team where he worked under O’Neill for five years.
O’Neill insists that Keane possesses the personality and the will needed to rejuvenate the players at Celtic and reclaim the Scottish Premiership title from arch rivals Rangers.
The former Aston Villa boss believes that the leadership qualities that Keane displayed as Manchester United captain and his experience in various managerial roles would provide the impetus necessary for Celtic to overthrow Rangers as champions.
“He’s got the personality for a start”, O’Neill was quoted as saying by BBC Sport.
“He was a massive player, an iconic figure in the game, one of the best midfield players in the modern day Premier League.
“He led and cajoled Manchester United on for almost a decade.
“He’s very strong-willed, and I know people then start to feel strong-willed people do not necessarily change or adapt.
“He has certainly got the capacity to do that – to motivate players, absolutely.
After working with O’Neill with the Irish national team, Keane had short spells as assistant manager at Aston Villa and Nottingham Forest.
Following Keane’s spell with the Irish national team as O’Neill’s assistant, the former Celtic manager revealed that his former understudy has learned a great deal and possesses the qualities required to take the reins at a top club like the Hoops.
“I worked with him at close hand.
“Sometimes in this game you get a reputation and that supersedes anything that you’re trying to do.
“Roy Keane has learned a great deal in the intervening years.
“He was my assistant at Ireland and I know that’s a totally different job, but has Roy Keane got the personality to manage at the very top? Absolutely.”