Promise Isaac, who captained Nigeria to the 2008 Olympic silver medal and scored 79 goals in 11 professional seasons in Turkey, died after collapsing at his apartment gym in Austin, Texas, authorities said Thursday. He was 31.

Issac was playing for the Austin Bold of the USL and the team said he died Wednesday night. Police said authorities were called after a report of a deceased person at Isaac's apartment building but further details were not available.

Austin Bold owner Bobby Epstein said Isaac collapsed at the apartment gym and no foul play was suspected.

Isaac played for Nigeria at the 2005 World Youth Championship and captained the Under-23 national team that lost the 2008 Olympic final 1-0 to Lionel Messi and Argentina. He also appeared in three matches for Nigeria's senior national team.

Isaac played for seven clubs in Turkey, appearing in more than 350 matches. He spent a season in Saudi Arabia before signing with Austin Bold, where he had three goals in 20 matches this season.

"The greatest loss a team can suffer is not on the scoreboard, it's the death of a fellow teammate," Epstein said. "On behalf of the Bold organization, we wish his wife, children and family strength and peace as they struggle to cope with his death."