Rugby-All Blacks concerns as skipper Read fractures thumb

* Read has surgery on thumb * Likely to be out for six weeks * Lions test series starts on June 24 (Adds detail) WELLINGTON, April 30 (Reuters) - New Zealand suffered a major blow to their preparations for the upcoming British and Irish Lions series when captain Kieran Read fractured his thumb in Super Rugby action on Saturday and was forced to undergo surgery. The number eight sustained the fracture to the base of his right thumb in Canterbury Crusaders' 48-21 victory over South Africa's Cheetahs in Bloemfontein on Saturday night and would be sidelined for around six weeks, the Super Rugby side said. The 31-year-old is expected to lead the world champions in the highly-anticipated three-test series against the tourists, which begins with the first test in Auckland on June 24. "(It is) extremely disappointing for Kieran and the All Blacks," Crusaders assistant coach Jason Ryan told New Zealand media. "The guy has worked so hard off the field to get his hand right from the surgery he had during the offseason and has been world class since returning to the field. "Obviously it's disappointing and will be concerning for the All Blacks." Read had surgery on his right wrist during the off season and only returned to Super Rugby against Japan's Sunwolves on April 14. He would have been looking forward to a few more outings with the Crusaders, including potentially the tour match against the Lions on June 10, before joining up with the All Blacks squad on June 11. A veteran of 97 tests since his debut against Scotland in 2008, Read took over as captain full time after Richie McCaw retired in the wake of the 2015 World Cup triumph under a well-crafted succession plan. Blindside flanker Jerome Kaino is also facing a race against time to be fit for the test series after undergoing an operation on a meniscus tear in his knee last Friday. Losing the experience of a combined 174 tests from his back row would be a major blow to All Blacks coach Steve Hansen, even if he has a wealth of loose forward talent to choose from. Openside flanker Sam Cane captained the All Blacks the last time Read did not start a test - against Italy last November - and the 25-year-old has long been identified as a strong candidate to succeed his Crusaders team mate in the long term. The Lions, who will be captained by Sam Warburton, start their tour with a match against a New Zealand Barbarians side in Whangarei on June 3. (Reporting by Nick Mulvenney in Sydney, editing by Ian Ransom/Amlan Chakraborty)