Former Blues centre-back John Heitinga has also paid his respects after the midfielder dies in hospital
Former Everton manager Ronald Koeman has paid tribute to Abubakari Yakubu after the ex-Ajax star passed away on Tuesday.
Yakubu died in hospital after he was placed on life-support following an illness earlier this week, the Ghanaian FA have announced.
Midfielder Yakubu played under Koeman for three years at Ajax before he left to join Vitesse on a permanent deal in 2005.
Koeman, who left Everton last Monday, tweeted: "Rest in peace Abubakari Yakubu."
Yakubu, who was 35, won two Eredivisie titles with Koeman before leaving on a season-long loan to Vitesse in 2004.
The former Ghana international played alongside ex- Everton defender John Heitinga in Amsterdam, and the Dutchman described his former teammate as a "great person".
Heitinga tweeted: "R.I.P. Abubakari Yakubu A warrior on the pitch, a great person off the pitch."
Ghana's FA tweeted: "We’re sad to hear the death of former Ghana, Ajax & Vitesse midfielder Abubakari Yakubu, our thoughts are with his family. may his soul RIP."