Celtic boss Neil Lennon has told Arsenal they will need to improve their offer for Kieran Tierney as he is "a far more rounded full-back" than Manchester United's £50million signing Aaron Wan-Bissaka.
The Gunners are reported to have made a second bid of around £25m for the Scotland international, which has been rejected.
Lennon is adamant Celtic will not be forced into a cut-price sale of any of their prized assets as they attempt to navigate a Champions League qualifying tie with Sarajevo.
He believes Tierney is a more complete player than Wan-Bissaka, who left Crystal Palace for United last month, and therefore expects offers that reflect his left-back's ability.
"We can't do anything about what clubs do in England," Lennon told a news conference.
"Fifty million for Wan-Bissaka is a lot of money and we feel that Kieran is a far more experienced and rounded full-back at this juncture in his career.
"He's an asset for us and we do have a value for the player and we rate the player very highly.
"'Disrespectful' is the wrong word but we're certainly not going to be pushed over in any negotiations and we're in a very strong position with regards to a number of our assets in the team.
"The club's valuation of Kieran has not been met and until then we don't have a discussion. He's a great player, a great talent. At 22, he's already achieved a hell of a lot and he has so much more to give to the game.
"He's our player. He's on a long-term contract. While it's a backhanded compliment for all the hard work people here have done over the years with Kieran, we don't want him to go.
"Some of the players who have left here in the last few years have gone on to do all right in the English Premier League. We think we know what we're doing in terms of developing players.
"But we don't want them in the Premier League, we want them here with us playing in the Champions League."