Joe Schmidt said replacing Johnny Sexton at half-time in Ireland’s 35-0 World Cup win over Russia was “tactical” as the Irish laboured before earning a vital Group A bonus point.

Sexton’s invention helped Ireland start well as they led 21-0 at half-time but the display dipped after his departure.

“We said maybe 40 minutes [for Johnny] this week,” Schmidt told ITV Sport.

“Maybe 40 or 60 next week. Hopefully then we get quarter-final qualification and he’ll be just fine to go.”

Sexton picked up a thigh strain in Ireland’s impressive opening win over Scotland and missed the shock defeat by hosts Japan last Saturday.

The Ireland fly-half was spotted putting a ice pack on his thigh area as he watched the second half in Kobe City but Schmidt played down suggestions he was “managing” the injury.

“Not really. He’s just kind of trying to cover his bases really. He certainly could have played on.

“That was my decision to take him off. We had three tries. We only needed one more [to get the bonus point].

Peter O'Mahony scored one of Ireland's three first-half tries

“It took a long time to get. I was pretty nervous there a for a while. Then we almost finished with three in the last 15 minutes.”

Despite the underwhelming nature of Ireland’s display, Schmidt refused to criticise his players, saying that the wet conditions had made handling difficult.

“It wasn’t for lack of line breaks. I thought there was a bit of cutting edge play from us.

“Just the conditions….you go into contact. As soon as the ball got squeezed, it kind of slipped out like a bar of soap.”

Jordi Murphy lasted only 27 minutes before having to go off with suspected rib damage

Murphy forced off by suspected rib damage

Schmidt added that back row Jordi Murphy, only called up to the squad last weekend as a replacement for injured Jack Conan, was being “checked out” by the Irish medical staff after only lasting 27 minutes because of suspected rib damage.

“He got squeezed in the ribs. He may have popped a rib.”

In his upbeat post-match assessment, Sexton insisted that the Irish were “delighted to get a good win and get back on the horse”.

“To pick up the bonus point was exactly what we were looking for tonight. To keep them to zero – there were a very well-organised team – they made life difficult for us at times.

“There’s lots to work on. On to Samoa now which is a big game to finish the group.”

Joey Carbery was a late withdrawal from Ireland’s replacements after feeling ankle irritation following Wednesday’s training session but Schmidt insisted that decision was precautionary.

Coach Jones hails Russia’s display

Russia’s coach Lyn Jones heaped praise on his team’s display against the world’s second-ranked nation.

“I’m absolutely delighted. It’s a big day for Russian rugby and we came through with five stars,” said the Welshman.

“Our players stood up today… and we knocked the Irish boys back.

Captain Vasily Artemyev, whose enthusiastic post-match interviews in a strong Irish accent have been a feature of the tournament, was characteristically ebullient about his team’s display.

“A magnificent die-hard attitude from our boys,” said Artemyev, who was educated at Blackrock College – the Dublin school attended by Brian O’Driscoll.

“We came second best, but we’re not broken after this game.