Latvia had justified their position at 117th in the world rankings but nothing could dampen the liberating effect on Friday of Martin O'Neill's appointment as Republic of Ireland manager. Several players spoke of a more relaxed atmosphere than under Giovanni Trapattoni, giving a shot in the arm to Roy Keane's pre-match assertion that Ireland do not have "this monster" for an assistant manager, while the pundits focused on the "freedom" of O'Neill's team to a man. It fell to the manager himself to lead calls for perspective.

"I accept the fact there will be sterner tests ahead, one of them on Tuesday," said O'Neill in the first answer of the press conference that followed the comfortable 3-0 defeat of Latvia. Poland in Poznan will certainly present a greater challenge for the new era of O'Neill and Keane, and its accompanying optimism, but a departure from the tactically rigid, ultimately downbeat reign of Trapattoni was established on day one. Hence the wholly positive reaction to the manner of Friday's victory at the Aviva Stadium.

O'Neill has promised several changes against Poland, who showed a fresh managerial start is no guarantee of success by losing 2-0 at home to Slovakia in Adam Nawalka's first game in charge on the same night that Robbie Keane, Aiden McGeady and Shane Long were seeing off the Latvians in Dublin. Poland are 69th in the world rankings, nine places beneath Ireland, having finished fourth in their World Cup qualifying group behind England, Ukraine and Montenegro and dispensing with coach Waldemar Fornalik as a consequence. They are expected to start Robert Lewandowski against the Republic despite Borussia Dortmund facing Bayern Munich on Saturday.

Millwall's David Forde is likely to reclaim goalkeeping duties for Ireland from Kieran Westwood and will be sure to have a busier night's work than the Sunderland keeper did against Latvia. O'Neill started with several players he knew and trusted for his international debut, Westwood and James McClean from his Sunderland days, for example, McGeady from his time at Celtic, but intends to give all the squad playing time as he assesses the options available.

In attack O'Neill has plenty, albeit without a proven alternative to Robbie Keane's remarkable output for his country – 62 goals in 131 appearances – but fewer in defence. West Ham United's Joey O'Brien is expected to join Ciaran Clark and Richard Dunne on the sidelines because of a hamstring injury, the same problem that has forced the Nottingham Forest midfielder Andy Reid to withdraw.

It was the supporting cast to Robbie Keane that provided the main source of encouragement against Latvia. McGeady and McClean were prominent out wide while Wes Hoolahan revelled in playing off the LA Galaxy striker. Retaining, even enhancing, that adventure against Poland would send confidence soaring under O'Neill. Long, Anthony Stokes and Jon Walters impressed in their brief substitute appearances on Friday and it will be intriguing to see the manager's permutation in Poznan. With no competitive fixture until after the World Cup next summer, the balancing act is currently about keeping everyone onside rather than fine-tuning the first XI. "I think we needed a kick up the backside," admitted Long at the weekend. "It is probably a little bit easier around the place."

That said, it will be vital for O'Neill to improve McGeady's confidence and contribution during his reign as Ireland manager and therefore to show the same faith that accompanied the winger's initial impact when they were together at Celtic.

The Spartak Moscow player's fine finish against Latvia was only his third goal in 62 games at international level and, having bemoaned the amount of defensive work he was asked to perform by Trapattoni, the 27-year-old should have one less excuse for that record under O'Neill. Not that he will be excused all defensive work by Ireland's new management team. Roy Keane admitted he previously criticised the likes of McGeady out of frustration that their potential was not being fulfilled. O'Neill remarked: "I was pleased with Aiden's input [against Latvia] but he's got things he still needs to do of course. Sometimes when we lose the ball Aiden decides that he'll walk back instead of getting into a trot, unlike McClean, but we'll forgive him."