Veteran keeper Shay Given is hoping the Republic of Ireland can blow Euro 2016 qualifying Group D wide open by getting the better of surprise leaders Poland on Sunday.
Ireland entertain the unbeaten Poles at the Aviva Stadium desperate to bounce back from November's 1-0 defeat in Scotland, their first reverse of the campaign to date.
With world champions Germany still favourites to finish top of the pile despite a less than auspicious start, the race for the second automatic qualification spot is well and truly on.
Given said: "It is huge. It's a big week building up to it now as well. It's one of the biggest games we will play in the whole qualifying campaign.
"Of course, Poland are a great team, but we are at home and we have got to use that advantage and try to get the win.
"It's not must-win yet, but it's must-not-lose, I suppose. We have all been here before in this situation the the qualifying campaign. We know how important it is.
"It is a huge game, of course, and ideally you want to win your home games and take some points on the road as well."
After victories over Georgia and Gibraltar, the Republic returned from Germany with a creditable 1-1 draw, only to succumb to Shaun Maloney's strike at Celtic Park in their final qualifier of 2014.
Their next two games in the group see them entertain the Poles and the Scots in Dublin and only a healthy return will see them maintain pace with the pace-setters.
Martin O'Neill's men are locked together with the Germans and the Scots on seven points, three behind Poland.
Striker Daryl Murphy is refusing to look any further ahead than Sunday's showdown at the Aviva.
He said: "I think there's still a lot to play for. This game now coming, we need to get a result. Especially at home, we want to put in a good performance and come out with something after the game.
"I wouldn't look too far beyond that, just look to the game on Sunday and see what we can do."
O'Neill and his players met up at their Portmarnock base on Sunday evening and got to work at nearby Gannon Park in Malahide on Monday morning.
Skipper Robbie Keane was due to arrive later from the Los Angeles Galaxy, as were Bournemouth midfielder Harry Arter, in the squad for the first time, and Stoke striker Jon Walters, who played 12 minutes as a substitute in Saturday's 2-1 home defeat by Crystal Palace wearing a protective mask over his fractured cheekbone.
Everton duo James McCarthy and Darron Gibson and Burnley defender Stephen Ward were among those who sat out training but O'Neill was not unduly concerned.
He said: "It's not surprising really for James as Everton have played four games in the last 10 or 11 days, Seamus Coleman too. Darron Gibson has a bit of a groin problem - he played yesterday.
"Stephen has just had a little bit of difficulty. He's had an injury which he is coming back from and he's getting looked at this evening, with the club's permission, and we might have to do something about that. He's hoping maybe two or three days on that he's okay.
"Jon is coming in and he's pretty upbeat. He's got a mask and played for the last few minutes in the Stoke game and did well to put himself forward for the game, and there is this week. I think he is feeling fine and will be in later today."
O'Neill will not be rushed in selecting his team for a huge game, and 38-year-old Given is determined to use this week to edge himself ahead of regular number one David Forde to claim his 128th senior international cap.
He said: "The goalkeepers in general, David and [Keiren] Westwood and [Darren] Randolph as well, we are all a tight team together and whoever he picks, we will support them.
"You do wish them well but at the same time, your personal pride and professionalism, you want to play in the game and because it's such a huge game as well, I would love to play on Sunday.
"But I don't pick the team, I have just got to work hard in training. I have been playing well at Aston Villa when given the chance, and hopefully I might get the nod on Sunday. But if not, I'll support whoever he picks."