Ex-England international Trevor Francis is recovering in hospital after suffering a suspected heart attack, his former club Birmingham City said.
Francis, who was Britain's first £1 million footballer, was taken ill earlier on Friday and is recovering in Birmingham Heartlands Hospital.
A spokesman for the npower Championship club wished him a "speedy recovery", adding they had been informed he had been taken ill by a Francis family friend.
A statement on the Birmingham City website said: "Everybody at Birmingham City FC would like to send our best wishes to club legend Trevor Francis following news that he is recovering in hospital from a suspected heart attack. The former Blues striker and manager is much loved by everybody associated with the club and we'd like to wish Trevor a speedy recovery."
Francis played for the Blues between 1971 and 1979 before becoming England's first £1 million player when he joined Nottingham Forest. He also managed Birmingham between 1996 and 2001.
Francis, 57, remains the youngest player to have featured in a first-team game for Birmingham having made his debut in September 1970 at the age of 16 years and 139 days. He is widely regarded as one of the finest players to have played for the club and helped them win promotion back to the old Division One in 1972.
He went on to score the winning goal for Forest in the 1979 European Cup final against Malmo, before helping the team reach the 1980 final against Hamburg, although he missed the showpiece match due to injury as Brian Clough's side retained the title.
He left Forest in 1981, going on to play for Manchester City, Sampdoria, Atalanta and Rangers.
He won 52 England caps and represented his country at the 1982 World Cup, and worked as a player-manager at QPR and Sheffield Wednesday, with whom he reached the League Cup and FA Cup finals in 1993, losing both to Arsenal.
He took over as Birmingham boss in 1996, and led them to the 2001 League Cup final where they lost to Liverpool on penalties. Since leaving Blues he has had a spell as manager of Crystal Palace from 2001 to 2003 and worked extensively as a television pundit.