Schalke 04 general manager Horst Heldt has revealed that talks are ongoing with Celtic over the sale of striker Teemu Pukki, describing the Scottish giants as "very persistent" in their pursuit of a deal.
Hoops boss Neil Lennon has been chasing reinforcements in attack for much of the summer, after losing last season's top scorer Gary Hooper during the close season.
Heldt has insisted that Pukki will not leave until Schalke's Champions League qualifier against PAOK is concluded tomorrow night, with the Bundesliga side currently without talisman Klass-Jan Huntelaar through injury.
He told STV: "There is still contact between Celtic and Schalke.
"Celtic are very persistent in trying to make the deal happen. It is open for a transfer but not until our Champions League tie is over."
Lennon has seen two bids rejected for Pukki in the last week, but is believed to be planning a third offer before the transfer window closes.