Arsenal have rejected a £50m bid from Premier League rivals Manchester City for forward Alexis Sanchez.
The 28-year-old, who scored 24 Premier League goals last season, is out of contract next summer and wants to play for City manager Pep Guardiola.
Arsenal have rebuffed all approaches for Sanchez, and would like City’s Raheem Sterling as part of any deal before Thursday’s transfer deadline.
But Guardiola is understood to want the Chilean as a straight purchase.
England forward Sterling, 22, has featured in all three of City’s games so far this season.
However he is not guaranteed a starting role at Etihad Stadium following the summer arrival of Bernardo Silva from Monaco.
BBC Sport understands Sterling would be interested in moving back to London should he become part of the Sanchez deal.
‘Arsenal in a world of trouble’
Sanchez joined Arsenal from Barcelona, where he played under Guardiola, in 2014 for a fee of about £35m and won the FA Cup for the second time last season.
Gunners boss Arsene Wenger said earlier this month that Sanchez would “respect” his decision and stay.
The Chilean made his first appearance of the season in Arsenal’s 4-0 defeat at Liverpool on Sunday, coming off for Alexandre Lacazette after 62 minutes.
Former Liverpool and England midfielder Danny Murphy says Arsenal cannot afford to lose Sanchez.
“If they let him go they’re in a world of trouble. They’re in a world of trouble anyway,” Murphy said on Match of the Day 2.
“He worked hard enough [at Liverpool] but as the game went away from Arsenal you could see him getting frustrated.
“His body language wasn’t good when he came off – in fact before he came off you could tell he was despondent.”
Analysis by BBC Sport’s David Ornstein
Arsenal’s stance remains that they have no desire to sell, unless huge money and a player – most likely Sterling – are offered.
The final 48 hours of the transfer window are sure to test their resolve, and while in theory it could still go either way, the most likely outcome remains that Sanchez will stay and see out the final year of his contract.