Malky Mackay has become the second high-profile former Celtic player to state that he wants to succeed Ronny Deila at the Premiership leaders.
Neil Lennon, the Norwegian's predecessor, told BBC Scotland this week he would be keen to return when Deila leaves at the end of the season.
Now Mackay, sacked by Wigan Athletic a year ago, has declared his interest.
"If Celtic wanted to talk to me, I'd certainly be keen to do that," the 44-year-old told Sky Sports News.
Former Watford and Cardiff City boss Mackay was subject to a Football Association investigation after leaving the Welsh club, when it emerged that he sent text messages containing discriminatory language.
However, the FA confirmed last year that no disciplinary action would be taken, highlighting "serious concerns about the circumstances in which particular evidence had been given and the reliability and completeness of that evidence".
Mackay recently told BBC Scotland that he wished for a quick return to club management and that Celtic was a "huge, worldwide job".
"I think the next five-year period at Celtic is a crucial one," Mackay said. "I think a record 10 titles in a row is achievable and a strong focus should be there.
"But, for that to happen, I think there is a detailed and strategic plan needed going forward. I think I could help with that and bring a fresh approach.
"I've got an understanding of the club and an ability for that to happen."
Mackay was speaking after Deila announced last week that he would stand down in the summer.
David Moyes, the former Everton and Manchester United manager sacked by Real Sociedad in November, remains the bookmakers' favourite for the job.
But the 52-year-old former Celtic defender, who is also believed to be interested in the vacancy at Aston Villa, said last week that he would be keeping his options open before making a decision in the close season.
Steve Clarke, the former West Bromwich Albion boss who was sacked by Reading last December, has had his odds slashed by one major bookmaker, who now make him third favourite behind Moyes and Lennon.
Republic of Ireland assistant Roy Keane - who had a short spell as a player with the Glasgow club and turned down the job before Deila's appointment in 2014 - has admitted he would like to return to club management, albeit he refused to talk specifically about the Celtic job,
Northern Ireland manager Michael O'Neill also opted to shun questions about the summer vacancy.