After Ireland launched their World Cup bid with such an emphatic win over Romania, I had been really interested to see what changes Andy Farrell would make to his team to face Tonga.

Many felt Farrell would rotate for this game, but he has named a really strong team and means business.

A near full-strength selection shows how seriously he is taking the challenge of Tonga, who will represent a significant step up in quality from what we saw from Romania.

Maybe Farrell feels the challenge of Romania wasn't difficult enough to get the players up to the level that he wants.

And with the South Africa match looming large, perhaps Farrell sees Tonga as the ideal preparation for the eagerly anticipated encounter with the Springboks in the Stade de France next week.

But opting against wholesale changes is still a gamble and we'll have to wait until Saturday night to see whether or not it's the right call.

Farrell prepared to take Sexton risk

One of the surprises in the Ireland team was seeing Johnny Sexton retain his place at fly-half. With 65 minutes under his belt against Romania, Tonga felt like a good opportunity to test Jack Crowley or Ross Byrne in the number 10 shirt.

Crowley looked sharp when he came on while Byrne will be desperate for minutes after sitting out the opener.

But clearly Farrell sees it differently, and with Caelan Doris, Hugo Keenan, Garry Ringrose and Tadhg Beirne among those keeping their places, he has shown that he is not afraid to put a lot of his heavy-hitters in for the second week in a row.

Before the Romania game, there had been a lot of questions over Sexton after his six-month absence. He answered them emphatically.

He may be 38 now, but he looked fantastic. He led from the front, scored 24 points and escaped without injury. He looked like he hadn't missed a minute of rugby and that was really exciting for Irish fans.

For him, he's in the final chapter of his career, so it's big that he looked sharp, fit and hungry. With the exception of the little knock he took on the wrist when he scored his first try, the opening game could not have gone any better for the Ireland captain.

But starting him this weekend is still risky. He will be a massive target for the Tongan players, who I'm sure are desperate to make a big impression in their first game of the tournament.

You could see Romania tried to target Sexton, too. They had little success, but Tonga are a much more physically imposing side.

While Romania couldn't quite muster up enough of a challenge, Tonga will bring some ferocious tackling to the table on Saturday. They will try to come off the line very fast in defence and nullify Ireland's attack.

If Sexton is seen limping or in pain during the Tonga match, a nation will collectively hold its breath because against Romania he proved once again how crucial he is to this Ireland team - and losing him for South Africa would be a monumental blow.

After all, we have just seen South Africa lose their starting hooker Malcolm Marx for the rest of the tournament. But clearly that hasn't spooked Farrell, who is making a concerted effort to maximise his players' preparedness for the Springboks.

Ultimately, the most important thing for Ireland is to build on that big win over Romania and emerge from the Tonga game without any major injuries.

The first half against Romania certainly wasn't ideal performance-wise, but Ireland looked ruthless and hungry when they stepped it up in the second half. People were worried about the heat but they showed no signs of struggling in the conditions. They adapted, executed and moved on.

The desire to go up and score that last try was telling, too. It was a revealing insight into Ireland's mentality: they're never satisfied. The game was won but they still had the hunger to put together one last team move and finish the game off in style.

It's part of the reason why they are the number one team in the world.

Ireland weren't the only ones experiencing a few teething issues during the opening weekend. Being in Bordeaux, I witnessed some of the organisational issues which have been highlighted in recent days.

The children singing the national anthems, the trams to and from the stadium and supporters not being able to get water at the stadium were all signs that things weren't going all that smoothly off the pitch.

But the competition will be better for it, just like Ireland will be better for having got a shaky start against Romania out of their system. It's just as well they did, too, because the matches are only going to get tougher from here.

Tommy Bowe was speaking to BBC Sport NI's Matt Gault