Grant Leadbitter has thanked Middlesbrough fans for their 'amazing' support following his return to boyhood club Sunderland.
The 33-year-old midfielder completed his move to the Stadium of Light on Tuesday following a six-and-a-half year spell at Boro.
Leadbitter signed for the Teessiders from Ipswich in 2012 and helped the club win promotion to the Premier League four years later, while making 500 appearances for the club.
But the midfielder has rarely featured for Boro in the Championship this campaign, hence his return to the Sunderland on a two-and-a-year deal.
Leadbitter, who came through Black Cats' academy, has taken a large wage cut to join the Wearsiders and said he couldn't turn down the opportunity.
And in a lengthy message on Middlesbrough's website, Leadbitter, who was a popular figure among Boro fans, thanked everyone at the club for their support.
"I couldn’t leave Middlesbrough Football Club without saying my heartfelt thanks to everyone for what has been such a wonderful and memorable part of my career," said Leadbitter.
"When I joined in 2012 I could never have dreamt of having a such a good relationship with the fans, and the welcome you gave me and your support over the years has been amazing.
"I can’t thank Tony Mowbray enough for signing me in the first place, Aitor and Leo for what they brought to the club and achieved, and Steve Agnew, who was absolutely fantastic to work with.
He went on to say: "A new challenge is now awaiting for me, I could not live with the regret of turning down this opportunity at Sunderland Football Club and I’d like to thank Steve Gibson and Neil Bausor for their support in making his happen."
Leadbitter wasn't the only player to leave Boro on Tuesday, after defender Danny Batth's loan spell was brought to an end.
The 28-year-old joined the Teessiders from Wolves on the final day of the August window and made 13 appearances for Tony Pulis' side in all competitions.
But, after Wolves enacted a recall clause in Batth's loan agreement, the defender has completed his move to Championship side Stoke for a reported £3million fee.
When talking about the move, Batth told Stoke's website: “I’ve joined a fantastic club and I’m looking forward to getting started.
"The transfer happened really quickly and now I’m just looking forward to finding my feet and training with the boys.
“I managed to get a few minutes with Benik (Afobe) on the phone. I’ve played with him twice in different spells at Wolves – I know him really well and we’ve kept in touch.
"He spoke volumes about the club and what the new manager is trying to do.
“As a club, with a fantastic fan base, everything is set for us to do well.”
Batth's departure could mean Pulis will now look to sign another centre-back before Thursday's deadline, while the Boro boss will also hope to bolster his attacking options in the final days of the window.