Porthen has been named on the replacements bench to face England on Saturday, delved into the Bok scrum sessions and said both the excitement of the match and having the opportunity to scrum excited him.
"It's almost safe to say that a scrum session (at the Boks) is tougher than what you'd expect in a game," said the Stormers star, who earned all three of his Test appearances in November last year.
"Ox (Nche), Boan (Venter) and all of the players are absolute beasts, and it's different every time you scrum against them.
"They are all different, so you learn a different skill each time. And it's not just the technical aspect of things that stands out for me. You have to be switched on every single time, so I've learned a lot in those sessions. Being able to go into that dark place is something I've learned a lot from in this environment.
"You just keep at it, because there are so many aspects of scrummaging. If you neglect one and master another, it doesn't help, so we just try to stay on top of it all the time, and for me, it's about simply taking it all in."
With his ability to pack down at both tighthead and loosehead being one of his traits that has impressed the Springbok coaches, the 23-year-old said he'll never shy away from a challenge.
"If a coach comes to me and asks for it, I'll say yes if it gets me in the team, especially if it's what's best for the side," he said. "I'm all for it. If it comes up again, I'll do it."
Of the prospect of facing England for the first time, the former Junior Springbok captain looked forward to the opportunity, but admitted that it would be a massive battle.
"It's always tough against England," he said. "History shows it's never an easy game. They are coming here this weekend, well organised, so it's going to be a difficult match, but we are looking forward to it."
The team had Thursday off to rest and recuperate after a tough week of training, and will return to the field on Friday for their captains' run.
Former England centre Jeremy Guscott admits he's disappointed he won't be able to see Springbok flyhalf Sacha Feinberg-Mngomezulu take to the field against England on Saturday.
New Zealand head coach Dave Rennie has named a team that could see two players make their All Blacks debut against France in the Nations Championship on Saturday.
Springbok flyhalf Manie Libbok is under no illusions as to the challenge England will bring in their Nations Championship opener at Ellis Park on Saturday.
England manager Thomas Tuchel has praised his side's character after they recovered from an early setback to beat the Democratic Republic of Congo and book their place in the 2026 FIFA World Cup last 16.
