West Ham winger Sofiane Feghouli is set to complete a £4m move to Turkish club Galatasaray, according to Sky sources.
The 27-year-old will fly to Turkey on Saturday to complete the move after just a single season at the London Stadium.
The Hammers need to lower their wage bill after signing a number of players, including Joe Hart on loan from Manchester City and Javier Hernandez from Bayer Leverkusen.
Manager Slaven Bilic has made five major signings ahead of the new Premier League season, which begins against Manchester United live on Super Sunday on Sky Sports Football.
Pablo Zabaleta, Marko Arnautovic and Sead Haksabanovic have also joined Hernandez and Hart at the East London club.
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They are confident they can secure a deal for Carvalho, but are hoping to pay less than his £40m release fee.
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The 25-year-old, who helped Portugal win Euro 2016, is a product of the Sporting academy and has scored nine goals in 137 appearances since making his first-team debut in 2011.
Sporting have recently signed midfielder Rodrigo Battaglia as a potential replacement for Carvalho.