Negredo scored a hat-trick in City's 6-0 Capital One Cup semi-final first leg thrashing of West Ham on Wednesday to take his goal tally so far this season to 18 in all competitions.
And Nasri believes the former Sevilla front-man is demonstrating all the qualities required of a top striker in the modern-day game.
"I think he (Alvaro) is the signing of the season so far," Nasri told Sky Sports' Weekend Warm-Up.
"He's scored plenty of goals, he can hold the ball, he can play, he can find the space, he's a good finisher and he works a lot.
"He's been really good for us - I think he is the complete striker."
While Negredo has scored just eight times in the Premier League, City have managed 57 goals from their 20 matches.
Nasri says he is unsurprised by the team's goal haul, insisting he expects City to maintain their rich vein of goal-scoring form.
"It's not a surprise when you see the quality of our offensive players," he said.
"It's just that this year we have an identity and philosophy about the way we play, that's the big change.
"I think that we are going to score way more and beat the record by Chelsea or United."
After a strong start for City following his move from Arsenal in 2011, Nasri struggled to find his best form under Roberto Mancini last season, regularly finding himself sidelined.
The attacking midfielder has credited the arrival of Chilean manager Manuel Pellegrini for bringing about a turnaround in his fortunes as a City player.
"Confidence is everything for a player and the new manager has come in and given me a lot of confidence and freedom on the pitch as well," Nasri said.
"We talk a lot and he reminds me a lot of Arsene Wenger when I first came to England who was like a dad to me.
"When I came to City it was different because Arsenal were like a family to me. I arrived here with some big players and to a manager that liked conflict and for me that was a big change and I needed time to adjust.
"With him (Pellegrini) it's just like it was before. It's like something that I know already and I really like it that way.
"There is more talk. You know what you're doing right and you know what you are doing wrong. You know why you play or why you don't and that's what I like."