Yakubu has undergone surgery on his ruptured Achilles and will now begin a nine-month rehabilitation.
David Moyes confirmed the latest news on the striker on Friday, but reported no additional injury set-backs following last weekend's drama.
The injury Yakubu sustained at Tottenham saw him go under the knife earlier this week in London.
He won't feature again this season and now faces a race to be back in time for the beginning of the 2009/10 season.
The news on Louis Saha is better though; the Frenchman's injury isn't as bad as it looked after he was withdrawn with a hamstring problem on Sunday.
He is unlikely to be back in time for the visit of Aston Villa though, with Victor Anichebe likely to step in to the striking void.
But there was further frustration for Anichebe's friend James Vaughan who travelled to Colorado for surgery on his injured knee.
Unfortunately, Dr Richard Steadman was unable to perform the procedure due to an injury of his own, with Vaughan now set to return to the UK.
Moyes also revealed that Nuno Valente would be out for 'the best part of the season' following his own knee surgery.
"We've got three players out for a long time (Vaughan, Yakubu and Valente) in a squad which was already thin on numbers," said the Everton boss.
Steven Pienaar is fit to continue, following his goalscoring return to action in the capital.
Everton: Howard, Nash, Neville, Hibbert, Yobo, Jagielka, Lescott, Baines, Arteta, Osman, Pienaar, Cahill, Fellaini, Castillo, Rodwell, Anichebe, Jutkiewicz, Gosling.
