The Spanish champions were beaten 2-0 by Bayern Munich in a pre-season friendly on Wednesday, but they bounced back to resoundingly beat the Norwegian outfit in Oslo with new coach Gerardo Martino in charge.
And right-back Montoya believes that the club are making good progress as they prepare to defend their Liga crown.
"It feels very good [to win]," he told the club's official website. "The match against Bayern was a bit more complicated because they've been training longer than we have, but our evaluations of the matches have been very positive.
"He's [Martino] given us a really good first impression. I'm sure we'll all adapt well."
Cristian Tello was among the goalscorers in the drubbing and the 21-year-old is confident he will challenge for a starting place at Camp Nou this term, despite the arrival of Brazilian superstar Neymar.
"I am aware that there will be a lot of competition, but I trust my ability," Tello commented. "It motivates me."