Hooker Hartley lost his place in Stuart Lancaster’s Rugby World Cup plans after being handed a four-week ban for headbutting Saracens’s Jamie George in May’s Premiership semi-final at Franklin’s Gardens.
It was the sixth suspension of Hartley’s career, while his charge sheet amounts to 54 weeks’s worth of bans for eye-gouging, biting, punching, verbal abuse and elbowing.
Despite the move, Northampton’s director of rugby Jim Mallinder reaffirmed Hartley’s importance to the team.
“Dylan has been a superb captain for the past six seasons – the most successful period in the club’s history,” said Mallinder.
“He will remain one of many leaders in the team and prove crucial support for Lee from both a playing and day-to-day perspective.”