Johnny Sexton returns to captain Irish in World Cup opener

The 38-year-old fly-half has not played due to a groin injury he suffered during Ireland's Six Nations Grand Slam sealing win over England.

"Hopefully I can go out and put up a good performance as I expect that of myself," said Sexton.

"There will be no excuses if I play below par."

Sexton was unable to play in any of Ireland's warm-up matches due to a ban for abusing the referee in his side Leinster's the Champions Cup final which his province Leinster lost to La Rochelle - a game he did not even play in.

"Once I knew the ban was there I have just been focussed on this match for last couple of months."

Sexton entering his fourth World Cup hangs up his boots on a stellar career at the end of Ireland's campaign.

He is desperate to sign off with a flourish and at the very least being the first Irish captain to guide the team beyond the quarter-finals.

He says not all of the memories are sour ones and the Irish were not fixated on their underwhelming record.

"Always get asked about the fact we never reached the last four but it has not always been a failed campaign," he said.

"We have been successful and come away with some great victories.

"I have some good memories but yes some have ended badly."

Head coach Andy Farrell has paired Sexton with his Leinster scrum-half teammate Jamison Gibson-Park but he sprang a few surprises elsewhere.

Veteran wing Keith Earls starts, but there is no place in the matchday 23 for Six Nations Grand Slam winger Mack Hansen.

Young Leinster lock Joe McCarthy gets his first World Cup start alongside province teammate James Ryan, the experienced Iain Henderson is on the bench.

Farrell, who has earned great plaudits for his stewardship of Ireland in the past four years following an initially rocky start, has also opted for youth on the bench as back-up for Sexton.

Munster's Jack Crowley gets the nod ahead of Sexton's more experienced Leinster teammate Ross Byrne.

Farrell said he had no fears about the younger squad members being over-awed.

"When you get to these tournaments and you are young you can get lost inside this arena," said Farrell.

"But we have experience in abundance who can keep everyone focused.

"From what I experienced as a player and assistant coach, those who do well are those who treat it as all about rugby and nothing but rugby.

"We have enough experience to make sure how we go about our business."

The world's number one-ranked side have on paper tougher games to come with robust Tonga on Saturday week in Nantes followed by defending champions South Africa and unpredictable Scotland both at the Stade de France.

Ireland team to play Romania (kick-off 14:30 BST):

Team (15-1)

Hugo Keenan; Keith Earls, Garry Ringrose, Bundee Aki, James Lowe; Johnny Sexton (capt), Jamison Gibson-Park; Caelan Doris, Peter O'Mahony, Tadhg Beirne; James Ryan, Joe McCarthy; Tadhg Furlong, Rob Herring, Andrew Porter

Replacements: Ronan Kelleher, Jeremy Loughman, Tom O'Toole, Iain Henderson, Josh van der Flier, Conor Murray, Jack Crowley, Robbie Henshaw

Coach: Andy Farrell (ENG)