Luther Burrell has sent an emotional social media message to Saints supporters.
The centre, who arrived at Northampton from Sale Sharks in 2012, played his final game for Saints last Saturday.
Burrell will be moving to rugby league side Warrington Wolves this summer.
The 31-year-old played 167 times for Saints, scoring 31 tries in the process.
He was a key man in the double-winning side of 2013/14 and has enjoyed some good form of late.
But he has decided now is the time to move on, and he took to Twitter on Wednesday afternoon to thank Saints supporters once again.
"I would like to thank everybody from the bottom of my heart for all the support over the past seven years," Burrell posted.
"Your love will always be remembered and my time at Northampton Saints will always be kept close to my heart.
"It's been one hell of a journey.
"Thank you for a great time and for all the great memories.
"I am looking forward to the future as I continue my career in the switching of codes joining Warrington Wolves and I am sending my best wishes for everyone at the Saints for continued success.
"If you fancy watching a bit of rugby league in this off-season, you know where to find it.
"Thank you, thank you, thank you.