Arsenal head into Sunday's crucial clash against Newcastle at the Emirates Stadium battling a mini injury crisis, with several key players facing late fitness tests.
Newcastle United captain Jamaal Lascelles has returned to first-team training after a 13-month spell on the sidelines with an ACL injury.
Borussia Dortmund are set to face a tough spell without their midfield dynamo Marcel Sabitzer, who has been ruled out for at least a month with a knee injury.