Robert Lewandowski insists Erling Haaland's impressive form at Borussia Dortmund does not necessarily mean the striker will be a world-class talent in years to come.
Haaland is one of the most sought-after talents in world football after scoring 80 goals in 79 appearances for Dortmund since joining the club in January 2020.
That is a goals tally only Lewandowski can match over that period among players from Europe's top five leagues, the Bayern Munich star having notched 107 goals in 90 games.
Haaland's 80 strikes have come from an expected goals (xG) return of 64, meaning he has scored 16 goals more than expected given the likelihood of the shot going in.
No player from the Bundesliga, Premier League, LaLiga, Serie A or Ligue 1 boasts such a large xG differential, with Lewandowski (12.3) behind Luis Muriel (12.4) in third.
While there is no disputing Haaland's quality in front of goal, however, Lewandowski has questioned whether the Norway international will remain as prolific in seasons to come.
"Haaland is a great player who is fun to watch," Lewandowski told Polish magazine PilkaNozna.
"But just because someone has great potential, it doesn't mean they will be a real star for many years."
Breaking down Haaland's goals with Dortmund further, he has scored 96 per cent of them from inside the box, compared to 84 per cent for Lewandowski over that period.
However, Haaland has scored far more goals with his left foot (80 per cent), whereas Lewandowski is predominantly right footed, netting 67 per cent of his from within 18 yards.
The duo are far from identical in terms of playing style, too, as pointed out by Lewandowski.
"I don't like comparing a 33-year-old player with a 21-year-old player because everyone has their own development," he said.
"But he's strong, fast, physical. His game is based on that. I have different qualities. And we don't know how he will develop..."
This season alone, Lewandowski has scored 10 goals more than Europe's next most prolific marksman in Karim Benzema (24 goals), with Haaland third on 23 goals.
The Poland international turns 34 in August, but in a warning to his rivals for the 2022 Ballon d'Or award, he does not believe he is yet at his peak.
"My performance tests are now giving better results than last year," he said. "As for the numbers, it seems my best time is yet to come. I feel better now than I did two years ago."