After an impressive 43-7 win over Suntory Sungoliath on Saturday, the Blues were left pondering the possible loss of their All Blacks locking contender for eight to 10 weeks.
The injury was suffered late in the first half of the game in Tokyo.
Coach Vern Cotter said: "This is a tough blow for Patrick, especially early on in the season.
"We accept injuries are part of our game, and we're wishing Paddy a speedy recovery knowing he'll still offer plenty to the group from a leadership perspective over the next weeks.
"This is a resilient group, and we've got a strong stock of locks to call on while he recovers."
A replacement captain will be named this week before the side plays the Yokohama Canon Eagles on Saturday.
The Blues made no race of their first win in the Cross-Border competition, scoring three tries in the first 15 minutes of the game. Lock Sam Darry, hooker Kurt Ekland and wing Caleb Tangitau all crossed with first five-eighths Stephen Perofeta landing two conversions.
Home wing Kotaro Matsushima scored after 31 minutes and the Blues led 19-7 at the turn.
In the second half, another brace of tries were scored with Taufa Funaki scoring in the 43rd minute and Tangitau getting a second three minutes later. With the change in personnel it was not until the 70th minute that wing Kade Banks and fullback Cole Forbes completed the try-scoring for the Blues.
Scorers: Suntory Sungoliath 7 (Kotaro Matsushima try; Nicolas Sanchez con) Blues 43 (Sam Darry, Kurt Eklund, Caleb Tangitau 2, Taufa Funaki, Kade Banks, Cole Forbes tries; Stephen Perofeta 2 con; Lucas Cashmore 2 con). HT: 7-19
Moana Pasifika made a bold start to their DHL Super Rugby Pacific preparation when racing out to a three-try lead over the Highlanders in Queenstown on Friday.
However, the home side's perseverance after that first quarter shock paid off with captain and flanker Sean Withy posting the first try of the home's response. And before the halftime break fullback Jacob Ratumaitavuki-Kneepkens marked his first run for the side by scoring and having another newcomer, former Wales international five-eighths, Ryhs Patchell land the conversion.
Wing Timoci Tavatavanawai scored to get the Highlanders within touching distance before Jo Nareki scored to claim the lead. Argentine international Martin Bogado managed an intercept to set up a try for replacement wing Sam Gilbert.
Moana Pasifika halfback Ereatara Enari was able to cross and, with Christian Leali'ifano's conversion, get within three of the Highlanders.
However, the home team ensured the win when Hayden Michaels scored late in the game.
Scorers: Highlanders 36 (Sean Withy, Jacob Ratumaitavuki-Kneepkens, Timoci Tavatavanawai, Jo Nareki, Sam Gilbert, Hayden Michaels tries; Rhys Patchell 2 con; Gilbert con) Moana Pasifika 28 (Sama Malolo, Pepesana Patafilo, Alamanda Motuga, Ereatara Enari tries; William Havili 3 con; Christian Leali'ifano con). HT: 14-21
The Crusaders, also have injury concerns with former Welsh and British & Irish Lions fullback Leigh Halfpenny suffering a shoulder injury that forced him from the field in their game with Munster in Cork.
Without their World Cup All Blacks, while Munster were without their Six Nations internationals, the Crusders were down 0-14 midway through the first half after local lock Gavin Coombes crossed twice. However a typically daring breakout involving wings Chay Fihaki and Macca Springer and second five-eighths Dallas McLeod, who found halfback Mitch Drummond in support to score the try.
McLeod was in the action again with 15 minutes left when beating three defenders to level the score at 14-14. However, replacement hooker Scott Buckley got the home team back in front with first five-eighths Joey Carbery landing what proved a vital conversion.
The clock was beyond 80 minutes when the Crusaders unleashed a series of assaults before replacement lock Jamie Hannah crossed after a five-metre maul. Replacement first five-eighths Rivez Reihana saw his conversion veer across the posts to give the home team the win.
Scorers: Munster 21 (Gavin Coombes 2, Scott Buckley tries; Joey Carbery 3 con) Crusaders 19 (Mitch Drummond, Dallas McLeod, Jamie Hannah tries; Tahu Kemara con, Rivez Reihana con)
The Chiefs suffered the biggest loss of the weekend when going down to the Robbie Deans-coached Saitama Panasonic Wild Knights who scored tries to hooker Atsushi Sakate in the 15th minutes and to halfback Taiki Koyama in the 22nd minute, both of them converted by first five-eighths Rikaya Matsuda.
Eleven minutes into the second half, Matsuda landed a penalty goal but the Chiefs got their first points a minute later when first five-eighths Josh Ioane scored and converted his try.
Former Australia Test wing Maika Koroibete put the issue beyond the Chiefs when crossing 25 minutes into the half while former Hurricanes and Hawke's Bay forward Mark Abbott crossed with six minutes to go.
Prop Aidan Ross did score another for the Chiefs, right on fulltime but the home team managed to score another to replacement back Kyohei Yamasawa a minute into injury time.
Scorers: Saitama Wild Knights 38 (Atsushi Sakate, Taikai Koyama, Marika Koroibete, Mark Abbott, Kyohei Yamasama tries; Rikaya Matsuda 4 con, pen; Yamasama con) Chiefs 14 (Josh Ioane, Aidan Ross tries; Ioane con; Riley Hohepa con). HT: 14-0
