Arsenal's latest bid for Celtic's Kieran Tierney has been rejected, but the two sides remain in negotiations over a deal for the young defender.
Tierney is a long-term target for coach Unai Emery, as he goes all out to strengthen his side for the start of the new season.
It is believed that the club had two initial bid rejected; one of around £15million and the second closer to £18m, before making the third believed to be around £25million.
Arsenal's budget for the transfer window is thought to be lean and has been the main issue in all the targets they have identified.
It is the same issue the club is facing with Crystal Palace's Wilfried Zaha, who is valued at around £80million while Arsenal are thought to be willing to give half the amount and include some players in the deal.
The club has also been chasing William Saliba, but they have not been able to meet Saint Etienne's valuation of the young defender.
The Gunners are in desperate need to add key players in defense, especially with Laurent Koscielny's future unclear after he boycotted the club's preseason tour.
The future of the likes of Mustafi is unclear as well, especially after a poor campaign last time out, where the missed out on the Champions League qualification.