Seamus Coleman has warned the Republic of Ireland's Group D opponents not to underestimate their team spirit as they attempt to book a trip to the 2018 World Cup in Russia.

Ireland have reaped seven of the nine points they have contested so far in the campaign despite having failed to hit the heights they scaled in France this summer.

An unconvincing victory over Georgia on Thursday evening coupled with a 3-1 win in Moldova three days later has left them level on points with Serbia - with whom they drew 2-2 in Belgrade in their opening fixture - at the top of the group and with high hopes of qualification, albeit at an early stage.

Martin O'Neill and his players have been stung by some of the criticism which has come their way and they know there are tougher tests around the corner, but skipper Coleman is confident they will make a fight of it all the way to the death.

He said: "We can play better, but one thing that we have in there is we have got a team, a group of lads who will do anything to win the game and will do anything for each other.

"That's what is great about coming away together. If you make a mistake, nine times out of 10, you have got a mate who is trying to help you out and that's important.

"We can always improve technically, but when we have got that base, it's important. We have had a tough game already - Serbia away, which is a tough game - and we got a point out there, and Austria is going to be a tough game now.

"But they won't look forward to playing us either."

Coleman has stepped into the limelight in recent months having been handed the armband during Euro 2016 with Robbie Keane and John O'Shea eventually playing only peripheral roles.

With Keane having now retired from international football and O'Shea no longer a regular starter, the Everton full-back has become a figurehead, and he feels his form has improved, particularly for his club following the arrival of new manager Ronald Koeman.

However, he has insisted positive comments he made last week about the Dutchman were in no way intended as a criticism of his predecessor, Roberto Martinez.

Coleman said: "I saw something during the week that I took a swipe at Roberto Martinez, and that definitely wasn't the case. I have never said a bad thing about a manager that I have played for in the past.

"Roberto Martinez was good to me and taught me a lot going forward. When you are asked to compare managers, you always look like you're hammering another manager, which is never the case.

"Every manager is different and I just wanted to clear that up in terms of Roberto Martinez. I never took a swipe at him and I would never take a swipe at a manager.

"I just want to improve and impress every manager I play for, and they're all different."