Former Northern Ireland and Arsenal defender Pat Rice has been admitted to hospital after being diagnosed with cancer.
Rice, 64, made 528 appearances for the Gunners and was assistant manager to Arsenal boss Arsene Wenger for 16 years before retiring in 2012.
The full-back also made 49 appearances for Northern Ireland.
"We can sadly confirm Pat Rice is in hospital receiving treatment for cancer," said an Arsenal statement.
"Everyone at Arsenal Football Club sends him our best wishes. Our thoughts are with Pat and his family."
Rice played for the Gunners over 14 seasons after joining the youth team, going on to win the league and FA Cup double in 1971 and captaining the side to further FA Cup success in 1979.
After a spell with Watford, he joined Arsenal as a youth team coach in 1984 before progressing to further coaching roles and enjoying great success as Wenger's assistant, winning seven trophies.
Wenger hailed the work of Rice upon his retirement in 2012 and the Northern Ireland man was appointed an MBE in this year's New Year's Honours list.
On Thursday, Wenger spoke again of his admiration and respect for the Northern Irishman.
"We are in touch with him but I trust his legendary strengths to get over that," added the Arsenal manager.
"Not only do we love him but of course we are very grateful for what he has done here."