Michu, the midfielder who helped Swansea win the League Cup in 2013, has been forced to retire at the age of 31.
Spaniard Michu top scored for the Swans with 22 goals in his first season after a £2m move from Rayo Vallecano in 2012.
However, within two years of helping Swansea finish ninth in the Premier League, he was playing fourth-flight football in Spain after a recurring ankle injury.
Michu spent the 2016-17 season with Oviedo and plans to move into coaching.
After starting his career with Oviedo, he played for Celta Vigo before joining Rayo Vallecano, and was capped once by Spain in 2013.
He scored twice in the Swans’ opening day 5-0 win over QPR at Loftus Road – manager Michael Laudrup’s first Premier League game in charge of the Swans.
Among the memorable strikes were two late goals in a 2-0 away win over Arsenal in December 2012, and a trademark cool finish in a 2-0 win at Chelsea in the first leg of the League Cup semi-final.
Michu also scored as the Swans crushed Bradford 5-0 in the final at Wembley to claim their first major English football trophy.
He ended the season with 22 goals as Swansea finished ninth. He was valued at £30m by the club, who had given the player an extended contract in January 2013.