The 30-year-old, who has won 67 caps and played in all three Tests for the 2009 British and Irish Lions against South Africa, will have surgery under a local anaesthetic on Thursday.
Bayonne said on their official website Phillips will miss Saturday's Top 14 derby clash against Biarritz, with the club's medical staff predicting an initial two week lay-off.
Wales kick off their autumn Test series against Argentina on November 10, a schedule that also includes appointments with Samoa, New Zealand and Australia.
He would be an integral part of that campaign, in addition to Wales' RBS 6 Nations title defence later this season.
Phillips, meanwhile, is currently a clear favourite for the Lions Test number nine shirt against Australia next summer.
Gilbert has released a new line of rugby cleats. The Gilbert Virtuo 8S is part of the exciting new product. Check it out.
The Barbarians are one of the top invitational rugby sides with a long history and classic rugby jersey.
The Nike Tiempo is a solid rugby cleat and one of few styles still made from full-grain natural leather.
The Lions get ready for their matches with this green training jersey. It's what the players wear. Get in the Gear!
A cool looking all black rugby cleat with the high performance adidas is known for. Get in the Gear!
Wear the crest of the British and Irish Lions on your t-shirt. A great look for the summer.
$29.99
The Lions are ready to get their Australia tour underway. They arrive in Perth on Monday.
The New Zealand All Blacks training jersey for 2013/14. Get in the Gear!
The USA Rugby Pro Alternate rugby jersey is perfect for any fan of the Eagles. Get yours to wear during the summer Test matches.
The NEW All Blacks 2013/14 jersey has arrived at World Rugby Shop. Dare to wear the colors of the All Blacks.
