The deal does not have to be completed in an hurry on transfer deadline day in the UK as the Portuguese League window is still ongoing and does not close in another three weeks.
Two years ago in 2018, the Hammers broke their transfer record for the acquisition of Felipe Anderson for £42m from Lazio,
where he scored a total of 34 goals in 177 appearances before moving to the London Stadium.
Anderson has not featured often under David Moyes in the Premier League this season, coming off the occasionally in the closing stages of their opening two games of the season against Newcastle and Arsenal.
He was also an unused substitute in their recent impressive victories against Wolves and Leicester City.
In a brief statement on West Ham"s website, a statement read: ‘West Ham United can confirm that Felipe Anderson has joined Portuguese side FC Porto on a season-long loan.
‘The Club wishes Felipe all the best for his loan spell.
Anderson joins a list of outgoings from West Ham during this transfer window, with midfielder Jack Wilshere being release from his contract after struggling with fitness issues since joining from Arsenal. Grady Diagana and Jeremy Ngakia also left the club as well.
⚪ Bem-vindo, Felipe Anderson
⚪Bienvenido, Felipe Anderson
⚪Welcome, Felipe Anderson#FCPorto #NaçãoPorto #BemVindoFelipeAnderson pic.twitter.com/zUGTcIBdE3— FC Porto (@FCPorto) October 6, 2020
The 27 year old Brazilian has made just 12 goals in 72 appearances for the Hammers in all competitions, guiding his team to 10th and 16th positions on the table in the last two years respectively.
His contract still runs for another two years for the Hammers.
Anderson will be joined at the Portuguese champions by Chelsea defender Malang Sarr who also signed on loan for the season.