The good news for the Blues is that Woodcock is the only new casualty on a list which already has Charlie Faumuina, Brad Mika, Liaki Moli and Daniel Braid.
Tevita Mailau will replace Woodcock and the Blues hope that there won't be too much of a reduction in the scrum power as they want the sort of advantage the Crusaders managed in their match against the Highlanders.
"Their scrum might come under pressure but they manage the situation well," Lam said of his rivals.
"We know all about their doggedness, they keep fighting, they work for each other in tough situations."
"That sort of mental resilience is part of the reason for their success."
Lam and Highlanders coach Jamie Joseph played their rugby through a similar era and they have stayed in touch and Lam thinks that both coaches will have a fair idea of the other's approach and tactics.
"The spirit they have regathered, Jamie has harnessed that and squeezed extra out of it."
"Many feel the Highlanders will break but we have not seen it yet and the Blues have to think they will not crack this round," Lam added.
"This is probably the biggest challenge we've faced so far, to go down there to that cauldron and play them."
"They deserve that by the way they are playing. We will have to be right on our game and the gameplan we use has to be spot on."
The Blues have a number of ways to play the Highlanders and having studied them they already know how they plan to play them.
"Now we have to go and train it," said Lam.
"They will have key guys back like Adam Thomson, Jimmy Cowan and Alando Soakai, they will be at home, they will be on a high after the result with the Crusaders and they will have some fresh, strong replacements."
