Celtic's Norwegian defender, Kristoffer Ajer, has warned they face a "great" team in Rosenborg in next week's Champions League qualifier.
Brendan Rodgers' side recorded a second 3-0 win over Alashkert, despite Jozo Simunovic's early red card.
But Ajer says Rosenborg will pose a much greater threat than the Armenians.
"Rosenborg are a really tough opponent with a lot of quality players," he said. "It will be a really tough game home and away."
Moussa Dembele scored twice either side of Simunovic's 11th-minute red card, with James Forrest adding a third before half-time.
That set up a re-match with Rosenborg, who Celtic scraped past 1-0 on aggregate last season, in the second qualifying round.
"When you play Champions League qualifiers, you meet quality opponents," the 20-year-old said.
"I know Rosenborg really well. Last year, they beat Ajax in the last round to go through [to the Europa League group stage], so they are a really top side and can really hurt you if you're not 100% up for the game.
"Rosenborg are a typical Scandinavian team. They are well organised and have a good squad, so I think that's their biggest strength.
"It's a well built team with a manager that has been there for many years."
'We hope Dembele will be OK'
Manager Brendan Rodgers must now juggle his defensive resources for next Wednesday's first leg at Celtic Park, with Simunovic suspended.
Dedryck Boyata and Mikael Lustig are not yet back from World Cup duty while German centre-half Marvin Compper is injured and unlikely to be fit.
"Every pre-season there is always an issue with centre-halves," Rodgers noted.
"Marvin was injured, it's his abductor, so we'll see how that is, but it's highly unlikely he'll be available.
"With Boyata, I don't know - I'll need to assess that over the next few days. With Mikael, it's a possibility but when he comes back he won't be fit and it'll take a couple of weeks to get up to speed."
A further concern saw French striker Dembele limp off in the second half of Wednesday's victory, but Rodgers is hopeful the injury is not too serious.
"We'll find out in the next couple of days," he said. "He just felt a bit of tightness in his hamstring.
"He is as fit as he has been since I've been here at this stage of the season so we hope it was just a tightness and he will be OK."
Celtic at least know what to expect from Rosenborg, after meeting at the same qualifying stage a year ago.
"They have made some changes, but their system is very much the same," Rodgers told BBC Scotland. "They play 4-3-3, like to pass the ball.
"I think they'll come here, similar to last year, and be very compact, very tight and try and not concede."
Rodgers suggested that his team's "appetite and hunger in the game was exceptional" as they beat Alashkert despite Simunovic's red card leaving them a man short.
"It was a very good win for us considering we played most of the game with 10 men," he added.
"We got three goals and could have had a few more. We dominated the game with 10 men."
Of the red card, Rodgers said: "It could have gone either way. I can see why the ref sent him off.
"It was a high boot on the player. In European football, when your foot is that high, you can expect a red card."