West Ham co-chairman David Gold is recovering well from cholangitis and septicaemia, his daughter Jacqueline said on Tuesday.
Gold went into hospital on Sunday after being taken ill on Wednesday evening.
Since then, the Hammers have been inundated with messages of support for the 74-year-old, who missed the team's crucial 3-1 win over Liverpool last weekend.
Jacqueline Gold said that her father is responding well to his treatment and wanted to thank all the people who have wished him well.
She said: "My father is still feeling very poorly but his consultant is very pleased with the way he is responding to treatment and we are hoping he will be well enough for surgery next week.
"I know dad would like to thank everyone for their support and best wishes and there is no doubt that Sunday's victory has helped lift his spirits."