Johnny Sexton will play his first game since March after being named in Ireland's team for Saturday's World Cup opener against Romania in Bordeaux.

That was the veteran fly-half's last competitive game when a groin injury led to his second-half substitution.

Sexton missed Ireland's three World Cup warm-up games last month as he was serving a three-match suspension.

The ban was imposed after Sexton was found to have been "confrontational and aggressive" towards match referee Jaco Peyper following Leinster's dramatic Heineken Champions Cup final defeat by La Rochelle in May - a game the fly-half had been forced to miss because of his injury.

Despite having no game time in nearly six months, Sexton, whose playing career will end at the conclusion of his fourth World Cup campaign, insisted that he "expects to produce a good performance" on Saturday.

"There are no excuses in that regard," said the 113-times capped fly-half.

"Once I got over the injury, then came the three games off, and once I knew that was there, I've just been focused on this game for the last couple of months."

Ireland team to face Romania: Keenan; Earls, Ringrose, Aki, Lowe; Sexton (capt), Gibson-Park; Porter, Herring, Furlong; McCarthy, Ryan; Beirne, O'Mahony, Doris.

Replacements: Kelleher, Loughman, O'Toole, Henderson, Van der Flier, Murray, Crowley, Henshaw.

Coach Andy Farrell's backs changes from the win over England six months ago see Keith Earls and fit-again Garry Ringrose taking over from Mack Hansen and Robbie Henshaw, while Munster's Jack Crowley is preferred to Ross Byrne as the bench back-up option for Sexton.

In the pack, Rob Herring is named at hooker, with regular starter Dan Sheehan not deemed ready to play in Saturday's opener following the foot injury he sustained in the warm-up win over England.

The other forward changes from the Grand Slam game see Joe McCarthy taking over from Ryan Baird in the second row, with Tadhg Beirne, whose recent Ireland appearances have been at lock, named in the back row as Josh van der Flier is included in the replacements.

Herring is given the number three jersey ahead of Ronan Kelleher, who also has had fitness issues in recent weeks.

McCarthy's selection will surprise some but Farrell insisted that the Leinster lock merited his inclusion and scoffed at any suggestion that he had opted for a "mix and match" side rather than picking his strongest available team.

"He (McCarthy) deserves it with the form that he's shown not just in the games that he's played but also in his preparation over the last 10, 11 weeks. He's really progressed his game," added the Ireland coach.

"There's no mix and match now. We've got a squad of 33 that we totally believe in and whatever side we put out is going to be a good side.

"That side is going to be the one that represents the group so no matter what side we put out at this stage, it's going to be one that's threatening and a determined one at that."

Farrell said Crowley's versatility had come into his thought process when deciding on the replacement fly-half berth.

"Jack has been playing well, travelling well.so has Ross. You've got to make a decision."

Ireland on 13-game winning run

Ireland go into the World Cup on the back of a 13-Test winning run stretching back to last summer's series victory over the All Blacks.

Since that triumph in New Zealand, Farrell's side have underlined their status as the world's number one team by beating South Africa - who they will face in Pool B - and Australia in the autumn Tests before clinching the Grand Slam in this year's Six Nations.

However, the Irish have failed to go beyond the quarter-finals stage at all previous nine World Cups despite having gone into several tournaments as one of the form teams.

Farrell's side will be expected to comfortably overcome the 19th-ranked Romanians at the Stade de Bordeaux.

Romania have never reached the knockout stages of the World Cup in eight previous attempts, while they have lost all nine meetings with Ireland, three of which came at the 1999, 2003 and 2015 tournaments.

Ireland's World Cup pool games

Ireland v Romania, Bordeaux, Saturday, 9 September 14:30 BST

Ireland v Tonga, Nantes, Saturday, 16 September 20:00 BST

Ireland v South Africa, Paris, Saturday, 23 September 20:00 BST

Ireland v Scotland, Paris, Saturday, 7 October, 20:00 BST