The back-rower, who has just joined the Warrington Wolves, was not selected for the current series against the Kiwis as he recovers from injury.
Westerman was impressed with England’s 14-point victory last weekend at the KC Stadium.
“I thought it was brilliant, I thought they did really well,” he said.
“They dug in well. They’ve pushed on from last year definitely.
“I said we weren’t far off last year, just getting pipped in both games, and this year we beat them, and it ended up being quite convincing in the end.”
Westerman played 22 out of 30 games for Hull FC this season as he battled several small, niggly injuries.
“Even if I was picked [against New Zealand] I wouldn’t have played,” he said.
“I’ve had a couple of injuries this year, it’s not been the best of years.
“I’ve been playing with a few injuries so this off-season was for me to get fully fit and prepare for Warrington and see what happens from there.
“I had a bit of a knee problem even heading into the back end of last year so that’s sorted now.
“It’s just about getting fit now and getting ready for next year.
The 25-year old has signed with the Wolves for the next three years.
Westerman, who broke into Super League with Castleford in 2007, has began pre-season training with Warringon.
“I’m right to train now,” he said.
“Everythings OK. It was no big deal but it was something I needed to get done.”
The forward is keen to be involved with England in the Four Nations on home soil in 2016.
“Definitely, that’s what it’s all about,” Westerman said.
“Playing well for Warrington will give me the best possible chance to be noticed in there.
“For me it’s all about Warrington this year, playing well for them, and I think it takes care of itself the international team.
“If you’re playing well you get picked.”