Glenn Hoddle is being treated in hospital after taking ill just before he was due to appear on BT Sport as a pundit on Saturday afternoon.
"Hugely worrying news that Glenn Hoddle collapsed at the BT studios earlier".
The Tottenham hero had appeared on BT Sport's Live Saturday Morning Savage show earlier in the day.
He added on social media: "Every one of us is right with you, Glenn, sending love and strength".
The official West Ham United Twitter account also sent out a message of support. Your friends, colleagues and the whole football family are with you'.
Hoddle, one of the most naturally gifted English players of the last 50 years, has been a regular on the TV channel in recent years as a pundit and presenter Jake Humphrey has tweeted to confirm the worrying news. Our thoughts are with you'.
The Professional Footballers" Association also said: "The thoughts of everyone at the PFA are with Glenn Hoddle, who is seriously ill and has been taken to hospital.
A club hero at Tottenham, where he played for the majority of a celebrated playing career before later becoming manager in 2001, Glenn Hoddle was capped 53 times by England and scored eight worldwide goals. Get well soon, Glenn'.
The ex-midfielder earned 58 caps for England before going on to manage the national side from 1996 to 1999.
He lost his job the following year after controversial remarks he made suggesting disabled people were paying the price for sins in past lives in an interview with The Times - the remarks all the stranger as he was an ardent fundraiser for disabled peoples charities.
He has three children Zara, Jamie and Zoe from his first marriage.