Tying down Georgios Samaras, Anthony Stokes and Joe Ledley is a priority this summer according to Celtic chief executive Peter Lawwell.
The trio all have a year remaining on their current contracts but Lawwell will sit down with them after the current campaign and look to secure them to long-term Parkhead contracts.
"We'll look at it all over the summer. We have a few weeks," he said.
"Sami has a year, Stokesy has a year, Joe has a year and we understand that. We'll start talking.
"We haven't started with them yet so we need to get that going.
"It's a case-by-case scenario. We don't say: 'Let's leave Joe Ledley's contract to August 27'.
"If it is right, we'll do it and we'll fund it through other parts of the budget."
