Woodward says the policy is due to the difficulties they're finding in landing their top transfer targets.
He is quoted by the Mirror, stating: "It's a multi-year squad evolution analysis.
"It's hard enough to get three players done in a transfer window. To get six or seven done is extremely difficult if you are getting proper talent.
"If you choose to churn every player because they are not good enough and you're not extending contracts, you are putting yourself at risk of execution. Sometimes you have to take a broader view."