Paul O'Connell's addition to Ireland's backroom team will be an "inspiration" for the squad, former international scrum-half Paul Marshall says.

"Andy Farrell has said he hopes that's going to lead to a 'bit of inspiration' in the camp," said ex-Ulster player Marshall, who won three Ireland caps.

"I've no doubt that will be the case."

Speaking to BBC Radio Ulster's Sportsound, Marshall said the respect O'Connell commands within rugby throughout the world means Ireland players "will look up to him" and inevitably take on board what the Munster legend says.

"I think it will be the technical advice first and foremost," Marshall said.

"If he's able to draw an extra percentage or two out of the players, then it's only going to be a positive for the Ireland team."

Ringrose will be 'midfield mainstay'

While Ireland are third in the Six Nations betting as they approach Sunday's opener in Cardiff against Wales, Marshall believes an opening-round victory would build momentum for the rest of the tournament, which includes home games France and England in Dublin.

"We saw when Ireland last won the Grand Slam in 2018, Johnny Sexton's drop goal in France to win the game," Marshall said. "That created a bit of momentum."

Marshall believes fit-again centre Garry Ringrose is going to be a key player in Ireland's campaign.

"He's certainly going to be the mainstay in the Irish midfield at 13. He offers a bit more of an attacking threat than any of the others.

"It will be interest to see if Stuart McCloskey, Chris Farrell, Robbie Henshaw or Bundee Aki join him."

Stander among those yet to sign new IRFU deals

With a number of high-profile Ireland players not yet having agreed contract extensions with the IRFU, Marshall says the tournament will offer them the chance to show their wares both to the national governing body and potential suitors abroad.

He said: "For example, there has been a lot of talk recently about the likes of CJ Stander as a potential Lions tourist, whether he will stay on with the IRFU or could he be whisked off to France on a big money contract.

"There will be some of those players who maybe have or maybe haven't got their contracts sorted out just yet and will certainly be wanting to put on a big performance."

The continuing prevalence of Covid-19 will mean a much-changed Six Nations, in terms of the squad and management all having to bubble at the team's base in county Kildare.

"On a usual Six Nations training camp, you would have been released on a Tuesday night to head home, spent Wednesday at home with your family and then come back down on Wednesday evening," added Marshall.

"Even where the team are training at the moment at Carton House, it's closed to the public and everybody else.

"I've read that even the staff there are being tested as well. Certainly Ireland are taking as many precautions as they can."