The Gunners have been locked in talks over Lemar for a number of weeks, and it looks like Monaco are extremely reluctant to allow the 21 year old to leave the club.
The sale of Mbappe to Paris Saint-Germain or Real Madrid would almost certainly lead to Lemar’s sale being blocked. Monaco have already lost three key players in Bernard Silva, Tiemoue Bakayoko and Benjamin Mendy this summer, and losing both Mbappe and Lemar as well is not something the Champions League semi-finalists would countenance.
It could help Arsenal in another way though. Arsene Wenger believes that PSG are focused on signing Mbappe rather than Alexis Sanchez, and if they do land the Frenchman, their interest in the Chilean would cease, leaving the Arsenal frontman with few options to move this summer.