West Ham United have confirmed Victor Moses will return to parent club Chelsea. Midfielder Alex Song and forward Emmanuel Emenike will also return to Barcelona and Fenerbahce respectively.
In releasing their retained list of players, the Hammers also confirmed Joey O'Brien had left the club after his contract expired.
Academy youngsters Elliot Lee, Leo Chambers, Amos Nasha, Nathan Mavila and Jordan Brown have also left the club, while academy players Tim Brown, 19, and Clark Bogard and Ross Elsom, both 18, have also been released.
Moses, who has made just one competitive appearance for Chelsea since May 2013, made 21 appearances for West Ham during the 2015-16 season.
Barring that brief appearance in the Community Shield defeat to Arsenal in 2015, the Nigeria international has spent the last three years away from Stamford Bridge. The former Crystal Palace starlet endured a disappointing loan spell at Liverpool during the 2013-14 season, but enjoyed a far more successful campaign at Stoke City the following year before injury struck.
West Ham's co-chairman David Gold explained on Monday the club intended to identify and bring in better players to replace those who will leave ahead of their move to the Olympic Stadium.
"What we have to ensure now is that we keep that momentum going when we move to the new stadium, and that means we will be bringing in some new players to replace the four loan players who have left us – Carl Jenkinson, Victor Moses, Emmanuel Emenike and Alex Song. Our intention is to replace them with better quality," Gold said on the club's official website.