Chelsea have pledged their full support to Frank Lampard following the death of his mother from pneumonia.
He is now a doubt for Saturday's vital Premier League game with Manchester United and the Champions League semi-final with Liverpool next week.
Chelsea offered their condolences and said in a statement: "The club will be offering all the support it can to Frank and his family at this time."
Pat Lampard, 58, was the wife of West Ham legend Frank Sr.
Her sister is married to Portsmouth manager Harry Redknapp.
She was admitted to Whipps Cross Hospital in north-east London on 14 April.
A statement issued by Lampard's agent said: "Frank and his family would like to thank all the people that have inundated them with wishes of support.
Wot Kuyt'e did
"Frank would also like to acknowledge and say thank you for compassion shown to him by (Chelsea) manager Avram Grant and all staff at Chelsea FC during what has been a terribly traumatic period for him and his family."
Lampard, 29, had missed the recent Premier League games against Wigan and Everton to be at her bedside.
He resumed training ahead of the Champions League semi-final first leg at Anfield and played in the 1-1 draw on Tuesday after his mother's condition appeared to improve, only for it to deteriorate again.
Chelsea's statement added: "Pat was a very familiar face to many people at Chelsea FC.
"Her unswerving support for her son's career was evident at virtually every game that Frank participated in regardless of where it was being played."She would always be there to watch him with Frank's dad. Pat will be deeply missed by everyone at Chelsea."
Free Football Tips