Jack Wilshere has had his West Ham contract terminated by mutual consent.
The former Arsenal and England midfielder has made just one appearance for the Hammers this season, in the 5-1 Carabao Cup victory over Hull.
The 28-year-old joined the club in 2018 but ankle and groin injuries have hampered his fitness.
He played 599 minutes in 16 Premier League appearances, and made 19 appearances in all competitions.
Wilshere said: "I can confirm that I have today agreed the termination of my contract with West Ham United.
"When I joined the club in the summer of 2018 I joined with great hopes and expectations and was excited to join the club I'd supported as a young boy.
"Unfortunately, despite all of my best efforts and intentions, it has not worked out as I'd expected. I have been fully fit for a large period of time at the club, including over the course of the last eight months - training hard everyday - but unfortunately I have not been given the opportunity to play.
"Although I am of course frustrated that I was not able to fully showcase what I am capable of at West Ham I remain convinced that I can still contribute at the very top of the game.
"I am still incredibly hungry, ambitious and desperate to play football and achieve success. I'm still only 28 and feel fit, strong and ready to play.
"I'm looking forward to the future and hope to make an announcement about the next stage of my career in due course."
Wilshere would have been out of contract at the end of this season.
He was offered a three-year deal when he signed for the club under the management of Manuel Pellegrini.
Porto keen on West Ham's Anderson
Porto are interested in signing West Ham midfielder Felipe Anderson on a season-long loan.
The deal does not have to be completed on Transfer Deadline Day in the UK as the Portuguese window does not close for another three weeks.
The Hammers broke their transfer record to sign Anderson for £42m from Lazio in 2018, where he scored 34 goals in 177 appearances prior to his move to the London Stadium.
Anderson has featured briefly for David Moyes' side so far in the Premier League this season, coming off the bench in the closing stages of their opening two games against Newcastle and Arsenal.