And he had to be stretchered off, with Calum Chambers coming on in his place with the task of keeping Costa and co. at bay.
Koscielny’s injury threatens to rule him out of contention for Didier Deschamps’ squad for this summer’s World Cup in Russia.
And it prompted a speedy message of support from Aubameyang, who’s unavailable for Arsenal due to being cup-tied in the Europa League.
“Damn it,” wrote the January signing on Twitter. “@6_LKoscielny courage bro.”
Speaking in the midst of Koscielny going down, BBC Sport pundit Chris Sutton discussed the seriousness of the injury to Wenger’s men.
