The Kangaroos take on a West Coast side missing injured star Nic Naitanui at Marvel Stadium on Saturday, leaving Xerri a ruck assignment opposed to Bailey Williams and Callum Jamieson.
Clarkson said it was a toss of the coin about whether to play two genuine ruckmen but ultimately wanted more run in his side.
He said it was a "really tough call" to pick the inexperienced Xerri ahead of 15-season veteran Goldstein, but did so with an eye towards rebuilding the Kangaroos' future.
"He's just had a great summer," Clarkson said of Xerri.
"He's continued to improve his application to his training and ultimately he is the future of our ruck division at the footy club.
"Goldy's been a great stalwart but the future in terms of the next 5-10 years is going to be with a newer guy coming in.
"He deserves his opportunity and he's just got the nod ahead of Goldy at this point in time."
An All-Australian and North Melbourne best-and-fairest winner in 2015, Goldstein is just five games short of reaching 300.
"He's disappointed, obviously. These guys are such proud men," Clarkson said.
"They've played the game for a long time and there's a reason for that - because they've got real pride in their performance.
"But he's also all about team and all about club, so he's taken it the right way.
"He knows he needs to perform well to give himself a chance to come back into the side."
North Melbourne will unveil No.3 draft pick Harry Sheezel against West Coast, with fellow off-season recruits Griffin Logue and Liam Shiels also set to make their first appearances in blue and white.
Bullocking forward Cam Zurhaar has been named despite a pre-season calf strain that had put him in doubt for round one.
"We've just got to manage his game time and make sure his energy's there for the contest, and hopefully he'll be able to make a solid contribution for us," Clarkson said.
It will be former North Melbourne player Clarkson's first game in charge of the Kangaroos since his "homecoming", following 390 games and four premierships in 17 seasons at the helm of Hawthorn.