The 26-year-old, who signed from Westley's old club Stevenage at the end of last season, was delighted to accept the armband.
He told the club's matchday programme: "He (Westley) named me captain for the first pre-season game and it wasn't made official until last week, but it was something I really relished. It was a challenge at the beginning of pre-season and now that I have been named it is really exciting.
"We have a new set of players, a relatively new manager, I think the fans are looking forward to it and now we have a new captain and it is something I am really looking forward to - leading the lads out in front of the fans for the opening game of the season."
Westley added: "John is a fantastic example to his team-mates in his professionalism on all levels. The intensity with which he works and his qualities as a human being make him perfect leadership material.
"He is brave enough to tackle me and intelligent enough to influence me. He is a fantastic communicator and he is forthright with his opinions. The team will benefit from his strength of character."
