Kobe - Scotland head into their Rugby World Cup match against Samoa on Monday knowing Ireland's surprise defeat by Japan has blown open up the race for quarter-final qualification from Pool A.

While it was always possible the Scots could lose to an Ireland side only recently knocked off top spot in the rankings by reigning world champions New Zealand, their woeful display in an opening 27-3 defeat left even loyal fans wondering if they could get out of the group.

But Scotland could yet be involved in a three-horse race for the two quarter-final spots with tournament hosts Japan and Ireland provided they can avoid further defeat -- although the ever-physical Samoans will have something to say about that.

Scotland coach Gregor Townsend has responded to the Ireland defeat by making major changes to his side, opting for a new back row with the vastly experienced John Barclay not even on the bench, while Darcy Graham and Chris Harris come into the backline.

"If we don't win all the next three games, we won't make the quarter-finals," said Townsend, with Scotland facing Russia and Japan after they play Samoa in Kobe.

"You always get a sense of negativity after a defeat or a performance where you don't play anywhere near your best, but there is also a sense that you can't wait for the next game," the former Scotland fly-half added.

"This week we see the physical challenge that Samoa bring. We need to not only match it but better it.

"We have to ride their tackles and work them hard in the set-piece.

"The changes we've made in the back row, we believe, will give us that carrying and line-out presence."

Samoa may have lost all three of their World Cup games against Scotland but, after starting the pool with a 34-9 win over minnows Russia, they will fancy their chances under the closed roof of the Kobe Misaki Stadium.

"They'll see us as like a wounded animal after that Ireland game and they are going to come at us," said Scotland strength and conditioning coach Sean Lamont.

"We are not dead in the water, there's still plenty to play for and for me it's about bringing that energy."

Lamont's first, 50th and 100th caps for Scotland all came against Samoa, leaving him well-placed to comment on what was required to beat the Pacific islanders.

"We need to box clever. If we just try and match them physically, that's playing into their hands," Lamont said.

"We know exactly what's coming. They are a nation of warriors."

Samoa reached the quarter-finals of both the 1991 and 1995 World Cups but it would be a major surprise if they matched that achievement in Japan.

A six-try win over Russia came at a cost, with Rey Lee-Lo and Motu Matu'u shown yellow cards for high tackles that saw both players receive three-match bans.

And number eight Afaesetiti Amosa was ruled out of the remainder of the World Cup after suffering a knee injury.

Samoa prop Jordan Lay knows Scotland especially well given he played for Edinburgh during the 2017/18 season.

"They're tough boys up there," he said. "They're really fit and I think that they're going to be looking to play a fast, high-tempo game.

"They're definitely a set-piece-focused team -- they're really strong at scrums and in their attacking maul, so they'll be looking to use that this time, no doubt, and that's what we're preparing for," Lay added.