Saracens' second-row Alistair Hargreaves has retired from rugby due to concussion.

Hargreaves, who made 79 appearances for the Aviva Premiership champions, hangs up his boots following medical advice.

"It's been a very tough decision to make. I've suffered a number of concussions in the last two seasons and after seeking medical advice I've come to the conclusion that the risk is outweighing the reward," Hargreaves said. "I have a young family, I have to make decisions that are right by them and although this was a hard decision for me personally it's one that I feel is the right one to make.

"The club have been amazing ever since I walked through the doors, but especially over the last twelve months when I've been suffering from injuries and concussion. They have been a constant source of support in a really emotional and difficult time.

"The first person I spoke to about this was Mark [McCall] and he was completely supportive of my decision. This club puts people first and their interests throughout have been 'what's best for me and my family' and I'm extremely grateful for the way they have handled the situation."

Hargreaves made four appearances for the Springboks and has been instrumental in the club's recent success.

Saracens director of rugby, Mark McCall: "The welfare of our players is of paramount importance -- we are fully supportive of Alistair's decision.

"Since arriving in 2012 Alistair has developed into one of the most influential players within the squad. He has played a key role in our recent success with his character, hard-work and leadership coming to the fore over the last four seasons. We wish Alistair, his wife Carmen and their young son the very best for the future."