According to The Scottish Sun, Celtic have seen their bid for St. Pauli left back Marcel Halstenberg stall - despite having agreed a fee for the German.
The Bhoys have been active in the transfer market so far this summer, bringing in four players; goalkeeper Logan Bailly, defenders Saidy Janko and Dedryck Boyata, as well as striker Nadir Ciftci.
Manager Ronny Deila may still be on the lookout for a couple more additions to his side ahead of the new season, and left back has been a position of concern for supporters over the summer.
Long-term incumbent Emilio Izaguirre is now 29 and doesn't look like his former self, with Charlie Mulgrew starting ahead of the Honduran against Stjarnan in midweek.
Now, The Scottish Sun believe that Deila has ramped up his efforts to sign St. Pauli's Halstenberg - even agreeing a fee with the German club for his signature.
However, the report also states that talks have stalled over a deal, and Deila is willing to move on to other targets if a move for the ex-Borussia Dortmund left back drags on for too long.
How much do Celtic need a new left back?
The Bhoys are fully aware of Izaguirre's recent struggles, hence why Deila chose Mulgrew instead for the Champions League game against Stjarnan.
The Honduran needs competition having been Celtic's undoubted first choice for around five years now, and a younger player - such as Halstenberg - would fit the bill perfectly.
Whether Celtic can now get a deal over the line for Halstenberg remains to be seen, but the lure of moving from the German second tier to Celtic Park could be too much for him to turn down.