According to BBC Sport, Celtic have agreed a deal to sign Hibernian midfielder Scott Allan for £275,000, with two players going the other way.
The Bhoys have signed four players so far this summer in goalkeeper Logan Bailly, defenders Saidy Janko and Dedryck Boyata as well as striker Nadir Ciftci, but manager Ronny Deila now looks set to dip back into the transfer market.
BBC Sport report that the Bhoys have now agreed a deal with Hibernian for midfielder Scott Allan, with Celtic sending Dylan McGeouch and Liam Henderson to Easter Road - though the latter will only leave on loan.
Allan, 23, has just one year left on his contract at Hibernian and will cost Celtic just £275,000, with Deila adding another talented young Scottish player to his side.
However, the deal will come as a major blow to Celtic's Old Firm rivals Rangers, who have been pursuing the player virtually all summer.
STV reported just last week that Rangers had seen a third bid for Allan rejected, with their Scottish Championship rivals adamant that Allan would not be sold to a direct rival.
The move is even more of a surprise given that Allan told the Daily Record last summer that he always dreamed of playing for the club he has supported all his life.
Instead, Allan is now on his way to play for their bitter rivals in a move which could certainly make him a real villain amongst Rangers fans.
Gers boss Mark Warburton may now look to other targets with Allan seemingly set for Celtic, even after landing Tottenham duo Dominic Ball and Nathan Oduwa on Thursday.