Rangers have rejected a second Bursaspor bid for Steven Whittaker.
The Turkish side have stepped up their efforts to sign the versatile Scotland international, offering a reported £600,000.
But Gers boss Ally McCoist is adamant he will not cash in on a player who has been a mainstay of the club's title-winning sides of the last three seasons.
"I don't even want to know what the new bid was," he told the Scottish Sun.
"I am trying to build a squad here, not dismantle one.
"Steven is a crucial part of that and I'm confident he will stay and we can clinch a new deal for him.
"Steven was superb for us last season. I have spoken with him and I feel his heart is here at Rangers."
The 26-year-old arrived at Ibrox in a £2million move from Hibernian in 2007 and has another year on his contract.
Bursaspor faced Rangers in the UEFA Champions League last season and bought Kenny Miller from the Scottish giants in January for £400,000.