The team he had joined only six months earlier was surging clear in the SPL title race, well on course to deliver Ambrose's first winner's medal at club level.
However, the chance of a league/Scottish Cup double was overshadowed by the looming Champions League last 16 ties against Juventus.
Ambrose wasn't going to miss any of this, even though he was not scheduled to return from the celebrations which followed Nigeria's African Cup of Nations success until a matter of hours before the first leg at Parkhead.
That Ambrose was brought back down to earth with a bump is an understatement.
His culpability in two of the three goals Celtic shipped that bitterly disappointing night led to serious questions about his insistence he was ready to play, and manager Neil Lennon's willingness to take him at his word.
Missing a training session before the return game in Italy - Ambrose has since explained he was on the wrong time zone and singing in the shower when his team-mates tried to warn him the bus was about to leave without him - did nothing to enhance his reputation.
He appears to have used the negative experiences as a wake-up call and, in the past year, has become one of Celtic's most consistent performers.
With the World Cup finals on the horizon - Ambrose gained invaluable experience of playing in Brazil when Nigeria contested last summer's Confederations Cup - he is probably the most focused man in Lennon's squad.
The Hoops boss has encouraged him to cut out the heart-stopping risk-taking, which pock-marked his report card from his first season at the club.
Now, alongside Virgil van Dijk, Mikael Lustig and Emilio Izaguirre, and in front of Fraser Forster, Ambrose has helped erect a green wall which the rest of the teams in the SPFL Premiership are finding impossible to break down.
Ambrose thanks God - literally - for the opportunity to develop into one of the first names Lennon puts down on his teamsheet every week, and, with his help, wants to make 2014 the year of his life.
To achieve this, the 25-year-old - who has played 74 matches for the Hoops since signing from FC Ashdod 18 months ago - plans to take his game to another level, and said: "Everybody wants to do better than they have done the previous year, so I need to try to do better than I did in 2013.
"You have to set your goals, and I just want to be a better player. You never know what achievements you can reach. I have the World Cup, and let's see what that may bring.
"At Celtic, we also have two trophies to defend, and let's see what happens. But, I know we are going to do better than we did last year, and maybe create things never been done before."
Ambrose will give thanks for anything and everything that comes his way this year, and believes he has the strongest possible ally on his side.
"I have to thank God for helping me make the right choice in coming to Celtic as I can't count all my achievements since arriving here," he told the Celtic View.
"I couldn't have done it alone. I have to thank God for helping me, but it has also been a collective thing, with my team, the management, the coaches, the technical staff, the fans and everyone around the structure of Celtic.
"The gaffer gave me a chance to play and prove myself, and he has improved me in every area of my game."
The rewards have been tangible, his Cup of Nations, SPL championship and Scottish Cup medals holding pride of place in his trophy cabinet.
It is the start of what Ambrose hopes will be a growing collection. But, having taken so long to get off the mark, he is not taking anything for granted.
"Everything you get in life is not easy, so, when you get it, you have to cherish it," said Ambrose. "That is what I do for every trophy.
"To win the league and Scottish Cup in my first season at Celtic just showed the good fortune I had in coming here. But, all this can only be done with great work. To achieve your goal, you must sacrifice a lot."
Which Ambrose has already done, not least in terms of the time he is prepared to take away from training or playing.
He is perpetual motion, and not even helping to look after the latest addition to his family, Angela - who arrived a matter of hours before he scored against Motherwell last month - has worn him out.
The energy comes from the desire to ensure his career trajectory continues to move in an upward direction.
And, with such an exciting 2014 laid out before him, he has every chance to maintain his goal.
But, Ambrose knows that, in this game, nothing comes to he who waits - you have to go out and grab it.
"We can't wait for it, we have to go out and earn it," is his mantra. "So, we will train harder, work harder in each game, and make sure we step up and concentrate and try not to concede goals."
If Ambrose can also find time to step forward and add to the two goals he has already scored this term - one behind last season's total - he revealed his trademark back-flips celebration could be surpassed.
"I will have something new for the fans as it is a new year," he teased. "And it will be something even better."