Saracens back-row forward Mike Rhodes will leave the Championship club at the end of the season.
Rhodes has helped Sarries win three Premiership titles and three European Champions Cups.
"His relentless work-rate and approach to the game have made him a central figure in all the club has achieved," director of rugby Mark McCall said.
Rhodes told the club website he had had an "unbelievable experience" since joining from Super Rugby club Stormers in 2015.
"On the field, the club has been very successful and I've been part of some great times," he added.
"I've been extremely lucky to have played with such a high quality team and I'm eternally grateful for being a part of this."
Saracens are on the brink of securing an immediate return to the Premiership, having beaten Ealing Trailfinders 60-0 in the first leg of the Championship play-off final.
The second leg takes place on Sunday.