Sean Jansen says he is relishing a "massive opportunity" to prove he can be Ireland's long-term starting number eight as he prepares for his home debut against Argentina.

With Caelan Doris and Jack Conan out injured, Jansen has been selected to start Friday's Nations Championship fixture with the Pumas at Aviva Stadium (20:10 GMT).

While squad captain Doris and two-time British and Irish Lion Conan are ahead of him in the pecking order, the 27-year-old Connacht back row is backing himself to become a regular presence in Andy Farrell's team in the lead-up to next year's Rugby World Cup.

"It's a massive opportunity for me," said New Zealand-born Jansen.

"I know that and I just can't wait to hopefully get out there and show what I've got and prove why I'm there.

"It was awesome to get my debut in the summer but I'm climbing higher. I want to put myself on the front foot to be that starting eight."

Dunedin-born Jansen joined Connacht from Leicester Tigers in 2023 and earned his Test debut in the summer after a string of commanding displays for the Irish province last season.

He marked his bow with a try in the win over Japan and came off the bench in the defeat by the All Blacks.

When asked what sets him apart from Ireland's other number eights, he said: "Hopefully just the way I play, the physicality I bring, the way I carry and tackle.

"Yeah, I don't know. I back myself."

Having closed the southern hemisphere Nations Championship leg with a humbling 40-21 loss to New Zealand, Jansen admits Ireland must tighten up defensively in this month's meetings with Argentina, Fiji and South Africa.

"I think defensive-wise, playing our game and playing our Irish system," he said when asked about improvements the team must make.

"I felt we might have just fell back a little bit over the summer tour, but the way we're training, we're flying and ready for these games coming up."