We should have seen it coming.

Northern Ireland had failed to scored in their six previous games on the road; the Republic of Ireland have badly struggled in front of goal for at least a year.

A stalemate was inevitable, and so it transpired, but it's the nature of the thing that worries you.

Michael O'Neill was right to talk up the positives of his side's display. There was a structure and an energy to the North that impressed. They passed the ball far better than their hosts and, in Steven Davis and Jamal Lewis, boasted the night's two best performers. 

Northern Ireland were not outstanding, but they look like they know what they're doing, or at least know what they're trying to do.

That is not the case with this Republic of Ireland team. Last night was the first occasion in six years that they've failed to score three games in a row, following on from the draw with Denmark and 1-0 defeat to Wales. All those misfiring performances have come at home.

In 2012 under Giovanni Trapattoni, Ireland were trounced by Spain 4-0 at the Euros, then outclassed in a 2-0 loss to Italy before drawing 0-0 in a Belgrade friendly against Serbia.

Here, we look at the options both managers had/have at their disposal around their respective three-game droughts, and the form those attackers were in at the time of selection.

2012 - THE TRAPATTONI ERA

Robbie Keane

The greatest goalscorer we've ever had was 32 heading to Poland and past his best but there was still life, and goals, in the Dubliner's legs. Moving to LA Galaxy in 2011 looked like it signalled a career that was winding down but his stats remained impressive.

He scored 18 times in 32 appearances in his first year in the MLS, but it was a loan spell at Aston Villa in January 2012, during the MLS off-season, that proved Keane could still cut it at the very top. He scored three times in six appearances, then returned to the States where he kept producing the goods.

He barely got a sniff of a chance in Poland as Ireland were given the runaround against Croatia, Spain and Italy, and didn't feature in the Serbia friendly. 

Simon Cox

Trap took a liking to the West Brom man, starting him against the Spanish (he was replaced by Jon Walters just after half-time) and keeping faith with him even after he'd fallen out of favour at the Hawthorns.

Cox failed to find the net once in 18 Premier League games in the 2011/12 season, though he did score three times in two FA Cup games. 

He came on in the closing stages against Italy and played the full 90 in the friendly against Serbia but once Trap moved on, Cox's international career died on the vine.

Jonathan Walters

Trapattoni gave the versatile Walters his first call-up in the autumn of 2010 and preferred him to Cox for the Euro 2012 play-off first leg in Estonia, an emphatic 4-0 win in which the Stoke man scored his first Ireland goal.

He scored 11 goals in all competitions for the Potters in the 2011/12 season but his most fruitful days in green would come later, under O'Neill. Trap liked to juggle his options, and though Walters did figure in all three games at Euro 2012 and then led the attack with Cox in Belgrade, his manager often shunted him out wide.

Shane Long 

West Brom's record signing has never been prolific, and scored just eight Premier League goals in 2011/12, but his ferocious work rate and willingness to work the channels has always endeared him to managers and fans.

He chipped a bone in his foot early in the campaign but was back by November and a key man in a decent year for the Baggies - they finished 10th in the table.

He lost out in the four-way battle to partner Robbie Keane in Poland; Long was an unused sub against Spain and only got 15-minute and 25-minute runs against the Croats and Italians respectively. 

Kevin Doyle

Doyle said earlier this year that "lads couldn't stand each other" going into the Euros as frustration simmered over the manager's preparation and training methods but he was the one who got the nod to start in that opening game with Croatia.

He was an established Premier League player with Mick McCarthy's Wolves by then but had only four goals in 33 league appearances behind him heading for Poland, after a nightmare season with the club. McCarthy was sacked in the February following a 5-1 hammering at home to West Brom.

Similar to Long, Doyle's all-round contribution won managers over. He started against Croatia and Italy but was withdrawn in both games and left on the bench for the Spanish humbling. 

2018 - A BARREN SPELL UNDER O'NEILL

Shane Long

The 2018 Shane Long is still in the Premier League, with Southampton now, and still a tireless, always willing runner but the goals have really dried up. Two league goals last term was a poor return - the first of those, last January, ended a 325-day wait for a goal -  and he's yet to get off the mark this campaign.

Long played 82 minutes of the Danish draw and the last 38 of the loss against the Welsh. He missed last night's defeat to the North with an ankle injury but he's the senior striker O'Neill keeps turning to and will play a central role in the mission to make the 2020 Euros next year.

Sean Maguire

He's been desperately unfortunate with injuries, which have really slowed down progress that was improving at a rate of knots. Maguire's incredible form for Cork City led to an Ireland call-up and a move to Preston. The Kilkenny man looked primed to kick on and nail down a green shirt but hamstring issues keep holding him back at key times.

Managed to get nine goals in 17 games for Preston last season despite a stop-start nine months. He's yet to score for his country but that's only down to his rotten luck with injuries. Maguire missed the Denmark and Wales games and then limped out of last night's game 13 minutes after coming on for clubmate Callum Robinson.

Callum Robinson

The former England underage international would have hoped to strike up a good partnership with Maguire for Ireland but it hasn't happened yet. He notched seven league goals last season and, after O'Neill drafted him into the Ireland set-up, endured a tough debut in the 4-1 hammering in Cardiff.

He's played in the last three games and looked quite bright but it's a tough gig playing up top on your own in this Ireland side. Robinson is also still waiting on his first international goal.

Aiden O'Brien

Played really well in the drawn friendly against Poland, scoring a good goal, and he earned a start against Wales in the ill-fated Nations League game at the Aviva.

O'Brien didn't get off the bench last night, O'Neill turning to Maguire and then Scott Hogan in search of an elusive goal.

The Millwall man is another who does a lot of good work without being reliably potent; he netted four times in 30 league games in 2017/18.

Scott Hogan

It's been a tough year for Hogan. He had a real purple patch at Brentford that caught the attention of Aston Villa but a high-profile move to the English midlands has proven difficult. Signed in January, Hogan only scored once before the end of the season.

The Manchester-born attacker was the man of the moment when he was banging them in for the Bees and there were real fears that England would snatch him from under Irish noses. O'Neill managed to get his man but Hogan's star has faded. He now looks like he's behind Long, Maguire and Robinson in the pecking order.

Jon Walters

The trusty old servant is still hanging in there but the body has seen a lot of wear and tear. Now 35, and on loan at Ipswich from Burnley, he ruptured his Achilles tendon against Bolton in September and has been on the sidelines since.

He played in the summer friendlies against France and the USA, himself and Harry Arter having a well-publicised falling-out with Roy Keane around that time. 

He'll always put his hand up for selection but injuries are catching up with Walters - he only played five times for Burnley in all competitions last term and failed to score.