The 76-Test veteran is a major doubt for the World Cup opener against Tonga after he joined fellow forwards Adam Thomson (elbow) and Kieran Read (ankle) in the treatment room.
However forwards coach Steve Hansen insists that Woodcock's injury is not serious.
"We're hoping he'll be okay," Hansen said. "He's got a bit of a twinge in his hamstring. They think it's just scar tissue from the previous hamstring he had a month ago."
Hansen also insists the All Blacks are not taking a risk by keeping Read in the squad - with the back-rower hoping to be fit before the knockout stages of the competition.
"He's world-class player and if he's going to be right by Canada (the final pool game) or even the quarter-finals it's not much of a gamble," added Hansen.
With Thomson also sidelined, Richie McCaw, Jerome Kaino and Victor Vito are the only back-rowers currently fit to face Tonga, although lock Sam Whitelock can slot in as a flanker if required.
Gilbert has released a new line of rugby cleats. The Gilbert Virtuo 8S is part of the exciting new product. Check it out.
The entire All Blacks apparel line has been updated for 2013/14. Check out the New Zealand All Blacks polo.
The Nike Tiempo is a solid rugby cleat and one of few styles still made from full-grain natural leather.
The Gilbert Blitz 8S rugby cleat is a great cleat at a great price of $69.99. Get a new pair of cleats today.
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.
The All Blacks Performance t-shirt is black with hints of blue from the training jersey. Very Cool.
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.