Fraser Forster's move to Celtic is in doubt because the Glasgow club have yet to match the goalkeeper's wage demands.
Celtic have agreed a £2m fee with Newcastle United for the 24-year-old, who spent the last two seasons on loan at Parkhead.
However, Forster's agent Mark Curtis has revealed that the Scottish champions' contract offer is currently not up to scratch.
Curtis told the Daily Mail: "I've spoken to Fraser today, I'm meeting him on Friday and I'll speak to [Celtic chief executive] Peter Lawwell again after we've had our meeting, to tell him whether he's going to be coming or not.
"We're a little bit away on the deal at the moment, but we'll see what transpires between now and the end of the week. Maybe we'll get a bit closer."
Hexham-born Forster came through the youth ranks at Newcastle but has never featured for the Magpies' first team.