Jack Wilshere was an unused sub in the defeat to Watford. (Reuters)

Arsene Wenger has revealed that Jack Wilshere was not brought on in Saturday’s 2-1 defeat to Watford because of an injury to Laurent Koscielny.

Wilshere had taken off his tracksuit top and appeared ready to be introduced with five minutes remaining.

But the midfielder retook his seat on the bench as Koscielny, who has been sidelined with an Achilles problem, was substituted for Rob Holding.

The decision sparked a chant of ‘you don’t know what you’re doing’ from Arsenal fans towards Wenger, who had claimed earlier this week that Wilshere ‘is in the best form I’ve seen him for a long time’.

Laurent Koscielny has been suffering from a calf problem. (PA Wire)
Arsenal fans chanted ‘you don’t know what you’re doing’ at Wenger. (Reuters)

‘I wanted to take [Alex] Iwobi off and they told me Koscielny had to come off because of his calf,’ Wenger explained after the loss at Watford.

‘So when we wanted to bring Jack on for Iwobi, it was our last sub possible, and Koscielny could not go on.

‘So I had to change Koscielny and bring a centre-back on, that’s what happened.’

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