A DIFFERENT breed of forward requires a different breed of defender to stop them.

With the likes of Riley Thilthorpe and Sam Darcy ushering in a new generation of goalkickers that are both big and strong, yet mobile and athletic, the profile of the key defender tasked with locking them down is having to change as well.

Fortunately for Geelong, Sam De Koning fits the prototype to do exactly that.

In the absence of sidelined trio Tom Stewart, Jack Henry and Jake Kolodjashnij last Thursday night, De Koning was handed the task of trying to limit the physicality and the threat posed by the 201cm Thilthorpe.

The big Adelaide forward had kicked 14 goals from four games heading into the Gather Round opener. But, in a statement Geelong win, De Koning kept him to just one goal from four marks and 13 disposals.

"He's obviously a big boy," De Koning told AFL.com.au afterwards. "He's grown the beard out and he looks pretty scary, I'm not going to lie. He looks like a new, young Charlie Dixon.

"I've played on some big key forwards before and I just wanted to come and play to my strengths. I tried to play off him a little bit and get up the ground at the ball and read it well and get involved in the play.

"I was happy with keeping his score down and making him have a quiet one."

De Koning's mobility and height – he stands at 204cm, towering over even some of the game's best key forwards – has led to Geelong coach Chris Scott trialling the gun youngster in a variety of different roles, including in the ruck.

Having impressed in the position late last season, where he replicated his older brother Tom's ball-winning and clearance abilities, De Koning started the year in the middle again this season. He's likely to move back there in due course, as well.

"He's had his challenges over the last couple of years with his body," Scott said.

"I've got to stop referencing 2022 at some point when it comes to Sam, but he was 19 and maybe in his second year and the way I looked at it … I was looking around thinking he was an All-Australian level key defender. That was his quality.

"He's just had some issues with his knee, in particular, but other bits and pieces as well that has limited him. But, off the back of a really good pre-season, we think he is ready to get at least back to that 2022 form. But I'm happy to say he's not going to play permanently as a key defender.

"His flexibility is going to be important to us. If I had to guess, I think he'd play more back. Riley Thilthorpe wouldn't have played on many guys that are taller than him. The days are gone when you can have a gun 190cm key defender, because these guys are just getting so big now. Sam's always going to have that strength for us."

It's back where De Koning settled on Thursday night. Playing in an understrength defensive unit, he was forced to anchor the group alongside teammates with just as much versatility in Mark Blicavs and Connor O'Sullivan.

But his job on Thilthorpe was crucial. Despite Adelaide notching 100-plus points for the fourth time in five games to start the year, the Crows' gun youngster had his impact limited by De Koning's own set of unique strengths.

"He's a big boy and he likes to body up," De Koning said.

"He likes to use his strength and aggression. You just try and not give him that. Me, as a lighter frame … he's athletic, but I know I'm athletic as well. You just try and get at the ball, jump at the ball and use my athleticism and reach and height.

"There's a lot of things you can do. But, obviously, he's a great young player and he's moving up and kicking a lot of goals. I was just trying to prepare mentally for a night of trying to stop him."

Stewart's withdrawal on the eve of Thursday night's match due to illness, compounding the loss of Henry and Kolodjashnij to hamstring and groin injuries respectively, immediately heaped the pressure on De Koning.

In the knowledge he would be coming up against an Adelaide forward line featuring Thilthorpe, Darcy Fogarty, Taylor Walker and Dan Curtin, it made for an intimidating test of the side's depth. But it was one they passed with flying colours.

"I'm not going to lie, it was pretty daunting," De Koning said.

"Especially as a young back. But it really just puts that competitive fire in you. You want to show up because it's Thursday night, it's Gather Round, against Adelaide, you're starting off the weekend, they're on fire.

"That's why it's one of the best wins I've been part of. We're super, super happy. We knew they were going to come out and attack. We hoped they didn't score as much as they did, but we were happy we got into the game and came back.

"It's honestly one of the best wins I've been part of."

The Cats play their next three games at the MCG with 80,000+ expected for their home game against the Hawks on Easter Monday! 

The best way to secure your seat is with a Melbourne Flexi Membership and attend any Cats Melbourne with a bundle of General Admission tickets, with 2-ticket packages for just $49. Head to membership.geelongcats.com.au today!