WATCH - Martin O'Neill ahead of Ireland v Poland

Martin O'Neill preparing for his biggest game yet as Ireland boss
Martin O'Neill preparing for his biggest game yet as Ireland boss

Martin O'Neill has admitted he has yet to finalise his team ahead of the Republic of Ireland's vital Euro 2016 qualifying clash with Poland on Sunday.

O'Neill has spent the last week keeping his fingers crossed over a series of injury doubts, all the while considering options to plug potential gaps in his starting line-up.

Everton midfielder Darron Gibson, who would have been in contention to start in the qualifier at the Aviva Stadium, has already returned to his club after admitting defeat in his battle against a groin problem, although O'Neill received better news on Friday when full-back Stephen Ward and winger James McClean were both able to train in Malahide.

However, the team will not be named until the day of the game, and that means there is still time for men to force their way into his plans.

"I think there are positions up for grabs, like there have always been since I have come here, and I think any international manager would probably tell you exactly the same," said O'Neill.

"He's got an idea that he can formulate a couple of weeks beforehand, but the first time that you really consider it is when you have players at your disposal for the week of the game.

"Of course, we have had one or two players who for one reason or another, generally through injury, haven't really been available for the start of the week, so then you have to formulate different ideas, different plans for the players that you think might participate in the game.

"But overall, there have always been positions up for grabs here."

Ward and McClean have both been struggling with ankle problems and while the Wigan winger has been a regular member of the starting XI under O'Neill, it is perhaps the absence of Burnley left-back Ward which would cause him the greater consternation.

Marc Wilson can and has played at full-back, although has more recently been employed as a central defender by his country, while Ciaran Clark is also left-sided and could play in both positions.

However, there is a school of thought which suggests that any vacancy on the left side of the back four could be filled by Hull winger Robbie Brady, who has operated there in the past for both club and country.

Meanwhile, O'Neill has confirmed he is looking to push for a victory on Sunday and would not be satisfied with a draw against the Group D leaders.

"Naturally, we are at home and the onus is on us to try to get forward and try to win the game, and that's what we are going to try to do," he added.

"But there are a number of games left in the competition. You mentioned the top two places [qualify] automatically - it's a tough old group we are in, but we are going for it."

Watch O'Neill's latest press briefing with the media below:

Martin O'Neill Friday interview from Football Association of Ireland on Vimeo.