Leigh Griffiths has entered talks with Celtic over a new contract and a bumper pay rise.
The Scotland international's current deal already ties him to the Parkhead club until 2021.
Attracting interest from MLS club Sporting Kansas, Swansea and West Bromwich Albion in January, however, Griffiths has authorised his agents to enter talks with Celtic chief executive Peter Lawwell over a new agreement.
'My representatives are working behind the scenes to try and get me a new deal,' said the 27-year-old.