Arsenal could be without Henrikh Mkhitaryan for the Europa League Final after admitting they were 'hugely concerned' he would be unavailable.
Tensions between Armenia and Azerbaijan are ongoing and Mkhitaryan missed Arsenal's clash with Qarabag because of the issue.
And it has flared again ahead of Baku hosting the final, meaning the Armenia captain could miss out on the game against Chelsea.
Hostility remains between the neighbouring countries over the disputed Nagorno Karabakh region, where a ceasefire was declared in 1994 after fighting erupted several years earlier.
Those issues meant Mkhitaryan did not travel with Borussia Dortmund to a Europa League game against Gabala in October 2015, and Arsenal say they need assurances over their player's welfare before naming him in the squad for their upcoming fixture against the Blues.
The club said in a statement: "The safety and security of our players is of paramount importance.
"We are seeking guarantees from UEFA that it will be safe for Henrikh Mkhitaryan to travel to Baku for the Europa League Final, which both Arsenal and Micki require for him to be included within our squad.
"Acceptable guarantees have not been received yet, and we hope that UEFA will be able to supply these promptly.
"We are of course hugely concerned that the location of the final could lead to Micki not being able to play in a European final."
Arsenal reached the Europa League final, which will be held on May 29, after a 7-3 aggregate victory over Valencia.
