The phrase "corner flag" refers to a small flag stuck in the ground at each corner of a sports field, usually in games like soccer or rugby. Full definition
A cross through the left wing and into the right corner flag? (justarsenal.com)
Bellerin bombs down the other wing and does cross, usually to the far corner flag. (justarsenal.com)
At times liv can have seven midfielders so i think it is important for Sanchez and other side to oftenly get in the space near corner flag as the wing backs will have to retreat from midfield making five at back but giving us space in the centre of park... Sanchez and hopefully Welbeck / Ox will have to be totally on there game. (justarsenal.com)