The Hoops are known to be in the market to strengthen in several different areas before the transfer window slams shut on February 1, and Neil Lennon’s side going after a midfielder seems like a reasonable assumption.
And, according to the Newcastle Chronicle, the Scottish Champions have made enquiries about the availability of the South Korean international, who played for Celtic across a three-year spell between 2009 and 2012.
But his weekly wage packet is seemingly a stumbling-block, with the midfield schemer reportedly open to a return to Glasgow.
The 30-year-old initially left Celtic for Swansea City, who were then flying high in the Premier League, and has since had spells at Sunderland and now Newcastle – where he has made just three Premier League appearances this season.
Ki will know his next transfer could be his last big move in European football – so can you see him coming back to Celtic this month?
And is he the kind of player Lennon requires?
Let us know in the comments section below…