Vainikolo joins All Black prop Greg Somerville on Gloucester's injury list
Gloucester winger Lesley Vainikolo will miss the remainder of the season after undergoing surgery on his ruptured Achilles tendon.
The 29-year-old England international suffered the injury in Saturday's 22-16 Premiership win over Saracens.
Gloucester head coach Dean Ryan said: "Les is a massive part of our squad and it will leave a very significant gap.
"With the current injuries we have in the squad, at the moment this could not have come at a worse time."
Vainikolo went under the knife at the Cromwell Hospital in London on Monday and will be out of action for at least seven months.
He has made 17 appearances in all competitions this season and has scored eight tries. He won the first of his five England caps against Wales in the 2008 Six Nations.
Ryan added: "When it is appropriate Les will begin his rehabilitation process, but we appreciate it will be a long road and he will have all the support he needs from everyone associated with the club."
On 2 January Vainikolo was charged with causing grievous bodily harm with intent following an incident in Bath and he will appear at Bristol Crown Court on 13 January.