Ireland will need a "reality check" when reviewing their five-try Samoa victory to have any chance of beating Australia, warns boss Joe Schmidt.

The relieved new head coach admitted he was "nervous" ahead of his debut in the Ireland hot seat.

Two tries from debutant replacement Dave Kearney - one set up by older brother Rob - and further scores from Peter O'Mahony, Fergus McFadden and Sean O'Brien eased the former Leinster coach's international initiation.

But Schmidt admitted his side must improve out of sight ahead of their impending Aviva Stadium clash with Australia, in the second weekend of autumn international action.

Schmidt explained: "We'll get a reality check when we look at it again: too many line-breaks from the Samoans.

"And we can't afford to do that against Australia. If they get on top they are extremely dangerous.

"If we open up too many options for them, they will take them.

"We are very, very aware of the threat Australia pose.

"Our kicking out of the hand wasn't as good as it could have been at times.

"If someone manages to find Israel Folau, or Adam Ashley-Cooper next week, then we will find ourselves in trouble."

Schmidt confirmed Ulster flanker Chris Henry suffered a minor hamstring strain, leading to his half-time withdrawal.

The Ireland boss said Henry's progress will be monitored in the next few days, with the hope the issue was caught early enough for it not to develop into a major problem.

"We'll get a reality check when we look at it again: too many line-breaks from the Samoans" - Joe Schmidt

Schmidt hailed the contributions of iconic duo Paul O'Connell and Brian O'Driscoll - and backed both to step up their injury returns in the coming fortnight.

He continued: "I spoke to Brian after the game and he felt he could have gone the whole 80, but the tank was starting to run dry after 55.

"He was relatively happy to see Ian Madigan heading his way, but he really enjoyed himself.

"It wasn't vintage Drico but it's a step towards it.

"And Paul really enjoyed it, enjoyed stretching his legs.

"I thought he brought real value off the bench."

Frustrated with Ireland's ball retention, Schmidt conceded he hopes a final-quarter flourish can whet the appetite of supporters for the clashes against Australia and New Zealand.

He said: "We worked hard enough but we offered too much ball back to them.

"We made three times as many tackles as them in the first half.

"Going forward to next week and the week after I don't think we can afford to be that untidy with the ball.

"Young Jack McGrath showed a bit of vindication for the time and effort that he's put in.

"The first line-out try I thought was top-drawer.

"The second half we did actually put a few plays together that did result in a few tries as well.

"It's going to take a bit of time because people are looking to find each other, and the system is different from what has gone before.

"Maybe we were forcing a few passes that didn't need to be, and that led to a little bit of frustration.

"That led to a try-too-hard factor too, they frustrated themselves and the crowd at times.

"But I hope that people got a little bit more interested and excited in those last 20 minutes about what can be achieved moving forward."