MUCH has happened since Carlton's 10-goal defeat of Collingwood in round three.

The Magpies embarked on a 10-game winning streak while the Blues suffered a nosedive in form despite the two appearing at opposite ends of the football spectrum that April evening.

Eleven weeks later, with the Magpies firing and the Blues struggling, the result was once again a Carlton victory with a key match-up playing out much the same.

Andrew Carrazzo had been critical to the round three win, shutting star Scott Pendlebury out of the match while gathering 29 touches himself.

The following week Carrazzo broke his collarbone early in the loss to Essendon and the Blues went on to slowly lose all momentum.

But in his third game back since returning from injury, Carrazzo once again had a crucial role to mind a Magpie midfielder.

Pendlebury was sidelined with a leg injury but Dayne Beams has taken his game to a new level with some mentioning him in the elite category.

Again, a star Pie was nullified by the veteran Blue, with Carrazzo gathering 26 touches for good measure.

Carlton teammate Andrew Collins said Carrazzo's value to the team was not easily measured.

"He's super-important. He's our heart and soul. He's been here for 10 years and does all the hard things for us," Collins said.

"He usually plays on the best midfielder each week and gets the job done."

Blues coach Brett Ratten said Carrazzo's presence in the midfield helped consolidate the roles for those around him.

"I think it helps the dynamics in the midfield where it allows Chris (Judd) to do what he does as well as other players like Mitch Robinson. Because of Andy's ability to get the ball too it does put a fair bit of pressure on the opposition," Ratten said.

"That's something that he does really well and personally he thrives on that challenge as well to get that best midfielder or the most in-form player from the opposition each well."

Judd has spent much of his career at Carlton as the main focus of opposition teams, but he admitted life was easier knowing his fellow 28-year-old was nearby.

"He's a super-important part of our structures," Judd said

"To see him come back and have as big an influence as he has is a real testament to how hard he works. He is really important for us."

Luke Holmesby is a reporter for AFL Media. Follow him on Twitter - @AFL_Luke