Erling Haaland stole the show at the Champions League in midweek, emphasising the difficult moments the World Cup winner is now having.

Kylian Mbappe isn’t a young man used to being eclipsed. In his young career so far, he has an impressive list of accomplishments to his name including the Kopa Trophy, three Ligue 1 titles and the World Cup, having been the first teenager since Pele in 1958 to score twice in the closing.

It’s a stunning roll of success, yet in Paris Saint-Germain’s 2-1 Champions League defeat to Borussia Dortmund on Tuesday, that he was totally upstaged by the performance of Erling Haaland. It’s possibly the first time in his professional career he was outshone by a player his junior, and Haaland was able to do so in convincing fashion.

While Neymar could grumble from the combined zone about a lack of sharpness, due to what he clearly perceived as PSG’s overly cautious approach with a rib injury, Mbappe might have few such complaints.

Since his touchline spat with head coach Thomas Tuchel – when he was substituted against Montpellier on February 1 – he played a full role in three successive games before being rested for the 4-4 draw against Amiens just 3 days before the trip to the Ruhr Valley.

While his numbers have stayed impressive — he’s 24 goals and 16 assists in 29 matches this year — there could be little doubt he has been less effective in recent fittings, with his general contribution because the winter break on something of a slide.

In his last seven fittings, by way of instance, he’s scored three goals and made two, quite decent figures for the average player, but Mbappe has long proven that he is of a superior quality to his peers.

Though he provided an assist for Neymar in Signal Iduna Park using a trademark burst of stride to the box, then a true square pass for his Brazilian counterpart to turn in from close range, he was much too easily nullified for extended periods and typified the offensive malaise his side revealed throughout.

While there were many disappointments from the PSG side, former Germany global Klaus Allofs picked out the striker as being the greatest let down to the Ligue 1 champions.

“PSG lacked cohesion, creativity in their drama going forward,” he said to L’Equipe. “They lacked freedom and rhythm. They improved after an hour, but their defensive midfielders were non-existent. Marco Verratti crossed the line when he was booked for arguing at the end of the match and he dropped the ball too often.

“However, for me, the most disappointing was Mbappe. He barely participated in the match. He was clear.”

The striker wasn’t helped by a surprise change to a 3-4-3 formation which saw him perform as the central forward, depriving him of the space he wants to run. However, the operation simply continued the trend of recent weeks. He’s been considerably less sharp for a longer period than in any previous stage in his career.

Given that the figures involved, it’s tough to predict what Mbappe is undergoing now a slump as such, but it certainly represents a dip.

Apart from this 2017-18 season, when he moved from Monaco to PSG in a blockbuster late-August movement, he’s always punched his weight concerning his xG [anticipated goals] statistic — the measure of how many goals he’d be expected to score in the shots he’d taken.

In his breakout season with Monaco, his figures were dizzying: he scored 15 goals when his xG figure was 6.86 — he struck more than double the tally of the typical player. Last term, he struck 33 times for an xG of 27.94, while this year he still posts a decent 15 goals from an xG of 13.72.

Considering that the 3-3 draw with his former club on January 12, however, he’s scored four times but has an xG figure of 5.4 — a rare prolonged period when he’s fought in front of goal.

He’s down to other crucial offensive metrics during this period too: his big chance conversion percentage is 27.3 percent, down from a career average of well over 40%, while his overall conversion rate is around 16 percent – well below what’s expected of him.

A first major injury of his career, suffered back in August and which kept him out for six months, was certainly a disruptive influence on the effort. Meanwhile, the luck has played a part. Two of the eight events Mbappe has struck the woodwork in his Ligue 1 career have come in the past six weeks, so he isn’t misfiring by much.

But perhaps the most telling statistic is that he has already played 176 senior games in a career that’s barely four years old.

Having played on average over 40 clubs matches annually because he turned 17, it would be irrational to believe that a lull in his unbelievable trajectory wouldn’t occur sooner or later. But it will throw into doubt the wisdom of putting his own name forward to play in both Euro 2020 and the Olympics this summer — two extreme competitions that will run across all of this close-season period.

Even the young superstar might need to be closely managed to ensure he does no lasting damage, either physical or mental.

Mbappe’s accomplishments to this stage in his career are similar with any player in the history of this game, but this is proving to be a testing period. He can’t hog the spotlight all the time, but when his degree hasn’t picked up to its usual standard by the time PSG sponsor Dortmund on March 11 that could spell trouble for PSG.