Six of Celtic's next seven fixtures are outside of Celtic Park.
With the Europa League behind them, Celtic now face a season-defining two-week spell.
Come mid-March, they might be cruising in the title race with the momentum on their side and into the Scottish Cup semi-finals.
Alternatively, they could be further toiling to defend their title and facing the prospect of a trophyless season.
The first stop is Ibrox on Sunday for a huge league match, with Celtic trailing Rangers by two points after playing one game less, with Hearts six points ahead of the champions.
This is followed by a midweek trip to Aberdeen, before heading back to Ibrox in the Scottish Cup last eight and then hosting high-flying and tough Motherwell.
Six of their next seven matches are away from Celtic Park. This much-maligned Celtic group is about to be put under severe pressure after a rollercoaster first two-thirds of the season.
"We can expect a lot of twists and turns," stated a former Celtic defender. "I wouldn't be surprised if the league is decided on the final day. But they will have to do it over the next five or six games. You have to be relentless, otherwise they won't take the trophies."
O'Neill Now Has Selection 'Headache'
Although the victory over Stuttgart proving moot in Celtic's bid to reach the last 16 of the Europa League, it could yet prove significant.
The manager rotated a large number of his first eleven and some of the squad members delivered impressive displays to claim the club's maiden win in Germany.
Luke McCowan stroked home the winner after under half a minute and was a positive influence, while in the back four, Dane Murray stood out in a gutsy performance.
Murray especially stated his claim to start next to Liam Scales. A superb block stood out and he was assured when dealing with set-pieces.
But the most talked-about performance was saved for second-choice goalkeeper Viljami Sinisalo as he contributed significantly in a long-awaited shutout in half a dozen games.
The first-choice goalkeeper has been under intense scrutiny after a string of mistakes. The 26-year-old was called upon and made six saves, in a display labeled "flawless" by a club legend.
A club goalkeeping great is of the opinion Sinisalo performed well enough to start against Rangers on Sunday.
"He had some very good saves and looked composed when he had the ball and read the game well," was the assessment. "The manager has a tough call to make at the weekend. On that performance, I would be starting him. Give him a run in the team now."
The Celtic manager conceded that a number of individuals have given him "plenty to consider".
"[Sinisalo] was outstanding in the game, exceptionally. That's the name all round the dressing room," the manager commented. "He's got plenty of talent."
Viljami Sinisalo made a strong case to start against Rangers on Sunday.
'Critical' Rangers Challenge Awaits
The additional positive of Celtic's win was that they showed they can grind out a victory.
Over the years, Celtic have arrived and naturally looked to dominate the ball from the first whistle to the last against every domestic opponent.
But this less robust side had looked increasingly vulnerable in recent times, often letting in more than one goal per game.
Having not won at Ibrox in their last four visits and given Rangers have won their past 10 home matches, a demonstration of toughness in Germany was timely.
Might Celtic take a somewhat more cautious approach? Right now, it is all about winning.
"You don't have to have all the possession to win the game," observed an analyst. "You've got to put in the effort, defend well, get a bit of luck and have a good goalkeeper."
"Celtic have not played well this season, but they are hanging in there [in the league]. They retain a chance, with a match to spare. The players will take great confidence from tonight - the weekend will be a critical one."
