Haaland, 22, joined Manchester City in a £51.2m move from Borussia Dortmund earlier this summer.
It was hailed as a major transfer coup for the Premier League champions, who beat off competition from Real Madrid and Barcelona to sign the highly-rated Norway international.
Haaland scored an incredible 85 goals in 88 games for Dortmund and he is the bookies' current favourite to win the Premier League Golden Boot award this season.
But talkSPORT pundit Jennings insists there is no guarantee the striker will immediately adapt to English football.
"You know this formality, that it's just a given that Haaland will score 20 goals. I just don't see why we're so confident about that," said Jennings.
"Maybe he will. I'm not saying he won't. Maybe he will. But I would also say that coming to a new league is hard.
"Coming to a new team is hard. Coming to a new team that are already champions, so they don't need to change their game – you've got to fit into their system. They're the champions, you're not.
🤷♂️ “I just don’t see why we’re so confident about Haaland!”— talkSPORT (@talkSPORT) July 23, 2022
👀 “Look at the players who have come from the Bundesliga to the #PL…”
“What I find difficult is this guarantee around #Haaland!”
Rory Jennings says we should reserve judgement on Man City striker Erling Haaland! 🤔 pic.twitter.com/JPfXp4YUed
"Think about players that have come from the Bundesliga to the Premier League, they haven't exactly set it on fire. Kai Havertz, fine. Timo Werner, abysmal. Jadon Sancho, alright.
"There is a constant stream of players that have arrived from the Bundesliga and haven't been great and there's no guarantee that Haaland lands and scores."
Jennings' comments have divided opinion on social media.
"Had he only scored goals in the Bundesliga it would be fair but he bags for fun in the CL as well," wrote one Twitter user.
Another added: "Talking rubbish, if he stays fit he will bag 25 to 30 goals in Premier League."
Actually agree. I do think he will be a hit (sadly) but many a German league player has faded here. It’s chalk n cheese.— Closealdo (@Closealdo) July 23, 2022
Had he only scored goals in the Budesliga it would be fair but he bags for fun in the CL aswell— K (@Kieranbcfc2) July 23, 2022
People are just deluding themselves into thinking he will flop, he’ll destroy this league— Macauley (@macwills95) July 23, 2022
Been saying the same. He might turn out to be what everyone thinks, but the season hasnt started and they're making it sound like he's already gone 40 goals in 5 games.— Jeremy (@Jackfruitboss) July 23, 2022
A third replied: "Been saying the same. He might turn out to be what everyone thinks, but the season hasn't started and they're making it sound like he's already gone 40 goals in 5 games."
Haaland is expected to make his debut for Manchester City when they face Bayern Munich in a pre-season friendly in the United States on Sunday morning.
Pep Guardiola's side then face rivals Liverpool for the Community Shield on July 30 before taking on West Ham in their opening game of the Premier League season on August 7.
Featured Image Credit: Alamy & talkSPORT
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