The 30-year-old is wanted by Premier League newboys Sheffield United and Championship side Middlesbrough.
The Scottish champions triggered a clause in the player's contract in May to extend it for a further year.
Neil Lennon said: "Scotty will be here for another year. He has been a good player since he walked in the door. It's a big boost for the squad.
"He has made a big contribution in the goals column and that football intelligence and experience is always important to have around," added Lennon.
"There is a familiarity there for Scott going into the Champions League qualifiers next season. He is one we don't need to replace."
Since arriving at Parkhead he has netted 60 goals in more than 150 games.