Talking points ahead of the Republic of Ireland's match against Portugal

The Republic of Ireland head for Portugal on Wednesday evening knowing this month's fixtures could largely determine their World Cup qualification hopes.

After defeats by Serbia and Luxembourg in their opening two Group A games, Ireland know they need a drastic improvement against the Euro 2016 winners, Azerbaijan and Serbia if they are to maintain an interest in the tournament.

Here, the PA news agency takes a look at some of the talking points surrounding their daunting clash with Portugal in Faro.

The Ronaldo factor

Cristiano Ronaldo rarely needs an extra incentive to do what he does best, but the formal completion of his return to Manchester United on the eve of the game means the 36-year-old will take the field at the Estadio Algarve with a spring in his step as he anticipates the adulation of the Old Trafford faithful once again. Keeping him as quiet as possible will be a major focus for Ireland, although they will be acutely aware that Portugal's threats are many.

Fighting back

Stephen Kenny's men could hardly face a sterner test as they attempt to bounce back from humiliation in their last qualifier. Running out against Group A rivals Luxembourg at the Aviva Stadium in March, the Republic were expected to win and win well. In the event, Gerson Rodrigues' late strike secured a notable victory for the visitors and left Kenny dealing with the fall-out of what skipper Seamus Coleman later described as an "embarrassing night".

Crunch-point for Kenny?

Kenny has attempted to move away from the safety-first approach taken by some of his predecessors to play a more expansive brand of football, fuelled in part by the introduction of a series of promising youngsters. There have been some impressive performances, but results have largely eluded him – the Republic were unfortunate to slip out of the Euro 2020 play-offs on penalties in Slovakia, and pushed Serbia all the way in Belgrade before losing their opening qualifier 3-2. However, a return of one win in 13 games – and that against Andorra – since he replaced Mick McCarthy at the helm tells its own story and has added fuel to the fires of his critics.

Young guns

Dara O'Shea and Jayson Molumby in particular have emerged from the Under-21s ranks to suggest they could have futures at senior level, while goalkeeper Gavin Bazunu appears to have made the number one shirt his own in the absence of Darren Randolph. However, young frontmen Aaron Connolly, Adam Idah and Troy Parrott, who scored twice against Andorra, are yet to convince that they are ready to take up the challenge on the biggest stage.

Time for old heads?

If Kenny is excited at some of the emerging talent at his disposal, the return to form of one of his most experienced players could hardly have been better-timed. Shane Duffy established himself at the heart of the Ireland defence under Martin O'Neill and then McCarthy, but after a difficult loan spell at club level with Celtic last season, had slipped down the pecking order. However, Duffy's return to Brighton has seen him start all three Premier League games to date and report for international duty with confidence renewed.