There’s something in the water in north London.Both Tottenham and Arsenal are suffering something of an injury crisis with numerous first-team players currently sidelined.And Arsenal certainly didn’t have luck on their side when it came to injuries during their FA Cup fourth-round tie against Manchester United.After just 21 minutes, Sokratis had to be replaced by Shkodran Mustafi after suffering an ankle injury.But things could even worse for the home side in the second half.Arsenal were already trailing 2-1 when Laurent Koscielny had to be taken off.And the way the Frenchman sustained his injury was pretty sickening.Koscielny was tussling for the ball with Romelu Lukaku and had fallen back on the turf.Then, Lukaku’s studs inadvertently caught the defender on the side of the face with a lot of force.It looked pretty horrific and left Koscielny with a bloody face.

LUKAKU'S STUDS IN KOSCIELNY'S FACE

Take a look:

The 33-year-old was down on the ground for the best part of five minutes before it was decided that he could no longer continue.

He had to be substituted for fellow Frenchman Matteo Guendouzi as the home side pushed for an equaliser.

It was part of a double change as Unai Emery also threw on Mesut Ozil for Alex Iwobi as the Gunners tried to save their FA Cup campaign.

But with a Premier League clash against Cardiff City on Tuesday night at the Emirates, Emery may have a headache wondering who he’s going to play at centre-back.

One thing is for sure, Koscielny will have a headache tonight.