Photo: Carlos Avila Gonzalez / The Chronicle
The feel-good story of Nick Mullens continues to play in primetime.
On Tuesday, the 49ers' recently anonymous quarterback said third-string coach Kyle Shanahan told him he would stay the starter if the 49ers hosted the Giants on Monday night.
Mullens, 23, scored a second career start due to his impressive debut in front of a national crowd in a 34-3 raid on the Raiders on Thursday night. He completed 16 of 22 passes for 262 yards with three touchdowns and no interruption. His pass rate (151.9) was the highest rating of a 49ers quarterback since Alex Smith (157.1) on October 29, 2012.
"It was a great experience, but it's obvious next week," Mullens said. "A week is not a season in this league, so we have to keep things going."
Mullens, a naughty free agent whom Shanahan jokingly referred to as the 49ers' "secret weapon" last week, will be no surprise to the Giants. Matt Breida ran back, smiling as he was asked how New York could prepare for him other than the Raiders.
"I think they'll be like" Oh shit, this guy's good, "Breida said," and they'll bring a few more people there just for the litters he's made. "
Mullens has taken the job of C. J. Beathard, who supported him against Oakland for having a sprained right wrist. Last year Beathard was replaced as a rookie by Jimmy Garoppolo after he had gone in his starts 1-4. This season he went to 0: 5 after Garoppolo with a torn ACL went out of the race.
"It's tough … going through it two years in a row," said Beathard. "It's something that will make me stronger in the end. I think God is testing me. I think that makes me a better person and a better quarterback in the long term. "
Mullens, for his part, does not look too far ahead. And he's finished thinking about making a debut stifling Fox in a postgame interview with Erin Andrews.
"To be honest, I'm finished thinking about it," Mullens said. "It's time to get to the Giants. But it was a very cool moment. I try to give everything I have. And when your work pays off, it's exciting. "
Eric Branch is a staff member of San Francisco Chronicle.