Jack Crowley is more than capable of stepping up to fill the void left by Johnny Sexton's retirement, says Ireland defence coach Simon Easterby.

While Sexton is considered one of the finest players of his generation, Easterby is confident Crowley will not be overawed by the challenge.

"Jack's always had that confidence," said Easterby.

"That's not just now, it's what he was like when he first came in.

"I experienced Jack in Bloemfontein with the Emerging tour and he impressed all of us with the way he handles himself. He demands high standards, not just of others but himself.

"That's the mark of a young man that is driving to be really successful."

Crowley has nine caps and provided back-up for Sexton during the World Cup.

But while being Ireland's starting out-half represents a huge step up for the 24-year-old, Easterby has no doubts over Crowley's temperament or skill-set.

"He would have learned a huge amount from his time with Johnny, as would all of our 10s, Harry (Byrne), Frawls (Ciaran Frawley) and Sam (Prendergast) coming in," added Easterby.

"We've got a really good blend of players in that position. Guys who are really hungry to take the baton on and Jack's certainly one of those and the other guys will be pushing each other to try and force our hand in terms of selection.

"It's a really nice group at the moment and there's a bit of a void to fill I guess but that's what losing a player like Johnny leaves. All four of them, Sam included, are really working hard to fill that and try to emulate and better what was done before."

'France defeat wouldn't spell the end of Irish title hopes'

Ireland begin their bid for back-to-back Grand Slams with a daunting trip to Marseille to face France in the tournament opener on Friday (20:00 GMT).

Games between Ireland and France have decided the destination of the title over the past two years, with France winning the Grand Slam in 2022 and Ireland achieving that feat last year.

Ireland have lost on their past two visits to France, but Easterby says Andy Farrell's side can still win the title even if they begin their campaign with a defeat at Stade Velodrome.

"You can't win the Grand Slam, but you could certainly win the championship with losing one game," said Easterby.

"In recent history, Grand Slams are hard to come by but championships is a second prize and it's been done before, losing a game during the championship."

Both sides are aiming to put Rugby World Cup disappointment behind them. Ireland suffered another quarter-final defeat by New Zealand while France's hopes of becoming world champions on home soil were dashed by eventual winners South Africa at the same stage.

"This Six Nations is going to be really competitive," added Easterby.

"There's a new coach in Italy [Gonzalo Quesada], slightly different style probably. The French will be smarting with what happened in the World Cup, as will we.

"The Welsh have gone down a slightly different route, they are picking a lot of youngsters but they're always up for the Six Nations, Gats [Warren Gatland] gets them in a great place.

"England and Scotland will probably feel like they've transitioned from the World Cup and are in a good place as well. I don't think any two teams stand out."

Easterby said Ireland have not encountered any further injury problems since beginning their training camp in Portugal earlier this week with Mack Hansen and Jimmy O'Brien having been previously ruled out.

On newly appointed captain Peter O'Mahony, Easterby said: "Training really well. [He's] come back in great form and no bother on him today.

"He trained, it wasn't full contact but it was quick, scrummaging and mauling, all of that was done. As far as I'm aware, he's come through with flying colours. He's in good shape."