Joint-Chairman David Gold has thanked his family, West Ham United supporters, players and staff for their support after being taken ill.
Mr Gold was admitted to a central London hospital on Tuesday and was put on intravenous antibiotics and Tamiflu.
The Joint-Chairman, who received hundreds of messages of support from Hammers fans via social networking site twitter and a large card signed by Sam Allardyce and his players and coaching staff, has been visited regularly by his two daughters Jacqueline and Vanessa and other members of his family.
On Friday morning, Mr Gold had recovered sufficiently to tweet a thank-you message to all those who have wished him well: "Good morning. I'm over the worst. Still on intravenous antibiotics but feeling better. Thank you so much for your kind words of support. dg"
The previous evening, Jacqueline joked that her father would be desperate to be at the Stadium of Light this weekend, despite being poorly. She tweeted: "Thank you to everyone for your support. [Dad] knows life won't be worth living if he even thinks about going to football but I'm sure three points on Saturday will help his recovery."
Vanessa also tweeted her gratitude for the goodwill directed towards the Joint-Chairman from supporters and friends alike: "Thank you for all your get well wishes for Dad."
Everybody at West Ham United wishes Mr Gold a speedy recovery and looks forward to welcoming him back to the Boleyn Ground and Chadwell Heath soon.