The forward watched from the sidelines as Celtic fell to a 3-0 defeat in Portugal last week, on the day after he completed his move from Scunthorpe.
The 22-year-old does not feel the scoreline reflected the play and he is convinced Celtic can put the Portuguese side under pressure in the second leg of the Champions League third qualifying round on Wednesday.
"We've been talking about it," Hooper said. "There was nothing in it really other than set-plays and it wasn't a penalty.
"I think we've got every chance of getting through. If we attack them and press really high, I think we'll have no problem.
"If we get one we'll get a few and win 4-0 I reckon. I don't think they were the best at home.
"We have to get the ball off them quickly, press them high and get them on the back foot and take our chances."
Hooper scored as Celtic came from two down to draw with Lyon in the Emirates Cup on Saturday, then watched his team-mates launch a strong, late fightback in a 3-2 defeat by Arsenal the following day.
And he is convinced another comeback is on the cards.
"We have to cut the mistakes out - that's what pre-season games are for," he said.
"I thought we played well in the last half an hour against Arsenal.
"If we can press Arsenal like that, we can do the same on Wednesday."