It rounded off a memorable calendar year in disappointing fashion, though will certainly not overshadow the memories of Euro 2016 and the record 12-match unbeaten run O'Neill's team compiled en route to France.
However, having played this fixture just four days after beating Azerbaijan in a World Cup qualifier, O'Neill (left) admits he needs to look at future schedules.
"I think a friendly after a competitive game is maybe not something we would do again," he said.
O’Neill continued: “We will be fully focused to play again in March; I’ve told the players tonight’s result isn’t important. We have a big game against Norway to put ourselves at 10 points (in the World Cup qualification process) and in an even stronger position.
“Our priority was that we win the game on Friday night. If anything tonight was probably maybe a game we didn’t need with the injuries we had but we got some of our players who’ve had little exposure on the pitch; that was the bonus for us.”
Although Michael McGovern and Conor Washington had returned to England for treatment on injuries, the appetite to play for Northern Ireland, one that has been fostered in these good times under O’Neill, was epitomised by Jonny Evans.
The three-time Premier League winner became a father again last week and was offered the chance to skip this game by O’Neill, only to fly back in to Belfast on the morning of a game he played in its entirety.
“It’s unbelievable,” O’Neill added.
“He only came in this morning for the game, his wife’s had a baby and he went home for a few days.
“I gave him the option to miss the game and he came back in to play, I think that says everything about Jonny Evans, in terms of his attitude to play.”
Alongside Evans in the starting line-up was debutant Matthew Lund of Rochdale, while Shrewsbury’s Ryan McGivern and Ross County’s Liam Boyce were among those to see the field too.
“I don’t have a deep squad, that’s pretty simple,” O’Neill argued.
“We’re playing against Croatia who are bringing in young players who are at Napoli and Inter Milan. With all due respect, we’re bringing in lads that are at Shrewsbury and League One clubs — we have to be realistic when we ask them to come and play international football.”
Croatia’s night was thankfully not overshadowed by more crowd trouble, although 25 of their supporters were ejected from the home end after security moved in during the first half.
Both of their last two home World Cup qualifiers have been hosted behind closed doors due to previous crowd trouble, and a banner reading ‘Never Forget Vukovar’ was unfurled, a reference to a massacre that occurred in 1991 during the Croatian War of Independence.
On the pitch, after goals from Mario Mandzukic and Duje Cop, their night was capped off by a 30-yard rocket from Andrej Kramaric, who certainly did not show such ability during an ill-fated short spell at Leicester.
“I think he made a great move when he made it to the Bundesliga,” Croatian boss Ante Cacic said of the current Hoffenheim forward. “He made a big step forward; he’s playing impressively for the national team, he’s useful in the build-up play and he’s a great converter of chances.”
World Cup Qualifiers
March 26, 2017: Azerbaijan v Germany, San Marino v Czech Republic, Northern Ireland v Norway.
June 10, 2017: Azerbaijan v Northern Ireland, Germany v San Marino, Norway v Czech Republic.
September 1, 2017: Czech Republic v Germany, Norway v Azerbaijan, San Marino v Northern Ireland.
September 4, 2017: Azerbaijan v San Marino, Germany v Norway, Northern Ireland v Czech Republic.
October 5, 2017: Azerbaijan v Czech Republic, Northern Ireland v Germany, San Marino v Norway.
October 8, 2017: Czech Republic v San Marino, Germany v Azerbaijan, Norway v Northern Ireland.
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