"Frank would like to acknowledge and say thank you for the compassion shown to him by the manager Avram Grant and all the staff at Chelsea Football Club during what has been a terribly traumatic period for him and his family.
"Frank and his family would also like to thank all the people who have been inundating them with wishes of support."
Chelsea have given Lampard as long as he needs to be with his close family and it is not clear whether the England international will feature in Saturday's Premier League match against Manchester United at Stamford Bridge. Pat, whose sister Sandra is married to Portsmouth manager Harry Redknapp, has been a staunch supporter of her son throughout his career.
With husband Frank, they were invariably to be seen at Chelsea's matches, home and away, both in England and Europe.
Lampard had said after Tuesday night's 1-1 draw with Liverpool in the Champions League at Anfield that he had only decided to play late on because his mother would otherwise have "had a right go at me".
It is understood that Mrs Lampard's condition deteriorated during yesterday and that the family had since been at her bedside.
