Harlee joined Brentford from Southampton, initially on loan, in November 2011 and made his debut as a late substitute away at Rochdale two days later. He quickly established himself at the heart of The Bees defence, featuring a further 27 times and scoring his first professional goal in the 4-0 win over Carlisle United, earning a two-year contract at the end of the season. Harlee made 56 appearances the following season as Uwe Rosler’s side took Chelsea to a replay in the FA Cup Fourth Round and reached the League One Play-Off final, performances which saw him share the Players’ Player of the Year award with Simon Moore and sign a new three-year contract.

As a 22-year-old, Harlee made 33 appearances in the promotion winning season of 2013/14 and has gone on to play 122 times in the Sky Bet Championship over the past three seasons. Last season, Harlee was voted the Supporters’ Player of the Year and leaves the club having scored ten goals in 249 competitive appearances for The Bees.

Co-Director of Football Phil Giles said: "Harlee has been an integral part of what this Club has achieved over the last few years. Not only is he a good player, he was someone who I found to be engaging company and who always had time for others, particularly with young fans at our open days. A great example of that was when he assisted at a road traffic accident outside Griffin Park after a game against Nottingham Forest in November 2015. On behalf of everyone at Brentford I'd like to thank him for everything he has done for the Club."

Brentford Head Coach Dean Smith said: “I would like to thank Harlee for his commitment to Brentford over the last six years. He was our captain last year and played to a level which earnt him recognition from supporters and peers, culminating in being awarded the Player of the Year award. He has been a major player for the Club over a successful period and a player I have thoroughly enjoyed working with. Unfortunately, we could not come to an agreement for a new contract and he has chosen to move on, we all wish him well for his future career.