Thomas Partey walked off the pitch and left a huge hole in Arsenal 's midfield as Tottenham countered to give themselves a 2-0 lead.
The Ghanaian midfielder, who passed a late fitness test before the North London Derby, was attempting to limp off injured just seconds before Tottenham attacked.
Arteta tried to get Partey back into position but by that point Heung-min Son had teed up Harry Kane who thundered the hosts into a 2-0 lead.
Partey was subsequently substituted by Dani Ceballos. "I can't see exactly what's happened but Thomas Partey has walked off the pitch and left them with that five v two, Gary," Jamie Redknapp said on Sky Sports. "That's where the problem comes from.
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