Williams out with knee injury

All Blacks and Blues midfielder Sonny Bill Williams has been ruled out of rugby for several weeks with a knee injury.

Williams aggravated an old knee injury this week and Blues medical staff said an x-ray yesterday showed a loose piece of bone in his knee joint.

He will undergo keyhole surgery later today in Auckland.

Blues medical staff expect that the second five-eighth will be unable to train for approximately four weeks.

The 32-year-old was due to assemble with the All Blacks squad next week to prepare for the first test against France - an update of his involvement from All Blacks management will be given on Monday.

Williams had returned to the Super Rugby competition only last month after fracturing his wrist which saw him sidelined for eight weeks.

The Blues are due to play the Rebels at Eden Park tomorrow night and remain at the bottom of the New Zealand conference.