Sonny Bill Williams injured again, in doubt for Rugby Championship test against Argentina

The injury struggles of veteran All Blacks midfielder Sonny Bill Williams continue.

The oft-injured 33-year-old second five-eighths has pulled up with a tight hamstring at the All Blacks training camp in Auckland and is in doubt for the opening test of the year in Buenos Aires.

Williams missed a large chunk of the Blues' Super Rugby campaign after undergoing a knee procedure, and only made it back on the field for their last match of the season. He made an appearance for Ponsonby in Auckland club rugby last Saturday in order to get some rugby under his belt.

The latest setback is inopportune to say the least, with the two-time World Cup winner locked in a tight five-way battle for a maximum four midfield spots for the global tournament in Japan.

A statement from the All Blacks confirmed Williams had a "tight hamstring" and would not play club rugby this weekend.

However, several All Blacks have been released to play club rugby, including Karl Tu'inukuafe (Takapuna), Ofa Tuungafasi (Grammar TEC), Patrick Tuipulotu and Rieko Ioane (Ponsonby), Dalton Papalii (Pakuranga), Brodie Retallick (Central Hawke's Bay) and Luke Jacobson (Hautapu).

The All Blacks squad will assemble again in Auckland on Tuesday afternoon for a camp before flying to Buenos Aires on Friday evening.