Saha likely to miss rest of season
"Louis has had an operation this week which will probably rule him out for the season," he told reporters.
"You pick up injuries and we try not to talk too much about them but we have a spate of them at this present time."
The France forward injured his ankle after falling awkwardly in the 2-1 Premier League home win over Fulham on March 19.
He is the club's top scorer this season with 10 goals, and had recently hit a rich vein of form with nine this year.
Everton, who are eighth in the standings with 40 points from 30 games, are also without Spanish midfielder Mikel Arteta (hamstring) and Belgium playmaker Marouane Fellaini (ankle).
"Mikel has been away in Spain for a few weeks, recuperating and recovering from his hamstring problem. He is due back over the weekend and we will see how he is," added Moyes.
Moyes also has doubts over Tim Cahill, Seamus Coleman and Jack Rodwell who all missed international duty with injuries.