The 30-year old striker has quit Turkish club Trabzonspor and has become available on a free transfer.
Janko was a target for the Hoops in 2010 when he was banging in goals for fun at Red Bull Salzburg but he opted to join Dutch club FC Twente instead.
However, it looks as though Janko could be back on the Bhoys' radar after walking away from Trabzon with the player himself admitting to interest in the Glasgow giants.
"I first came to speak to them a few years ago for two days of meetings when I was at Salzburg.
"I was in Glasgow to meet with (then-manager) Gordon Strachan in 2009 but I always remember meeting with Mr Lennon at the same time. I got on well with him.
"I was given a tour of the city, taken to the stadium which was fantastic and I could just imagine how it would be full.
"But for reasons not really to do with Celtic, more to do with the agreement I had with Salzburg, the move did not happen.
"I had already given my word to the owner of Red Bull I would stay with his club for one more season.
"Unfortunately, things have not worked out for me since."
For breaking stories and all the great banter like us on Facebook: facebook.com/tribalfootball