The 31-year-old joined Fulham for £1.85million from Dutch side FC Groningen.
“If I score every time I come off the bench it’s all right,” Nevland said.
“I’m a football player and I want to play as much as possible, and in that perspective it’s a bit disappointing.
“But we have two great strikers in Johnson and Zamora, so I have to be patient and do my job when I have to.
“I came on in a very pleasant time when Portsmouth had to score to equalise and there was a lot of space to run in and that’s what I like. Luckily I could take advantage of that.”
“The two strikers have been playing well, so I don’t understand why they’re getting any stick,” he added.
“It’s nice for me to get on and score when I get a chance. It was not that hard to get off the bench as there was space to run in.
“There have been a lot of games when I’ve come on and haven’t been able to make an impact.
“I proved that I can score at this level so I’ll leave it there.”