Henrikh Mkhitaryan’s availability for Arsenal’s Europa League trip to Qarabag is in doubt due to tensions between his homeland of Armenia and Azerbaijan.
The Gunners have been drawn with Sporting Lisbon, Ukrainian side Vorskla and Azeri champions Qarabag in Group E.
Some potentially tricky games are compounded by questions over Mkhitaryan’s availability for the trip to Azerbaijan, which is also hosting the Europa League final in the capital of Baku.
Tensions continue between Azerbaijan and Armenia over the Nagorno-Karabakh region, with a ceasefire 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, with the German club’s chief executive Hans-Joachim Watzke citing “safety concerns”.
In relation to the situation surrounding Mkhitaryan, UEFA said in a statement to Press Association Sport: “It is a standard procedure for UEFA to send letters of support to associations, clubs or embassies in order to obtain visas for players in order to be able to travel to another country and play in UEFA competition matches.”
Arsenal were one of four British clubs in Friday’s group stage draw at the Grimaldi Forum in Monaco.
Chelsea face tough assignments in Group L as they return to Europe’s second-tier competition for the first time since they lifted the trophy in 2013.
Greek Super League runners-up PAOK Salonika, BATE Borisov of Belarus and Hungarian side Vidi lie in wait.
Brendan Rodgers’ Celtic have been drawn alongside RB Leipzig and Salzburg – two clubs owned by energy drink firm Red Bull.
The German and Austrian clubs are both allowed to play in European competition after the UEFA Club Financial Control Body ruled last summer that they did not break rules on the integrity of UEFA competitions.
Rosenborg complete Group B and are a side Celtic know well having beat the Norwegian champions in a Champions League qualifier this summer.
Cross-city rivals Rangers have the toughest-looking draw of the British quartet.
Villarreal, Rapid Vienna and Spartak Moscow await in Group G as the Scottish side return to a European group stage for the first time since the 2010-11 Champions League.
Steven Gerrard’s men overcame Shkupi, Osijek and Maribor, before seeing off Ufa in the play-offs.
The first round of group matches is on September 20.