Swansea City have decided not to offer new contracts to midfielder Cedric van der Gun and defender Albert Serran.
Youngsters Kerry Morgan and Jamie Grimes have also been released by the newly-promoted club.
The four were among 14 Swansea players whose contracts expired at the end of the season.
Swansea say talks are continuing with goalkeeper Dorus de Vries, defender Angel Rangel and midfielder Tom Butler over new deals.
But midfielder Darren Pratley, who has been linked with a move to Premier League side Bolton Wanderers, is not expected to stay.
Van der Gun, a former Ajax and Borussia Dortmund winger, made 42 appearances for Swansea after joining on a free transfer from FC Utrecht in September 2009.
The 32-year-old Dutchman was a regular under previous manager Paulo Sousa, but had limited opportunities last season under Brendan Rodgers following Scott Sinclair's arrival from Chelsea.
Spanish defender Serran also notched up 42 appearances since making an £80,000 move from La Liga side Espanyol in July 2008.
According to Swansea, the 26-year-old is expected to join Greece side AEK Larnaca.
Striker Morgan, 22, leaves the club having made six first-team appearances. He spent the majority of last season on loan at Blue Square Bet Premier League side Newport County.
Defender Grimes, 20, failed to make any first-team appearances.