SANTA CLARA -- When the 2018 season concluded, 49ers quarterback Nick Mullens established himself within some elite company.

Mullens started the second half of the season and averaged 285 passing yards per game. He finished last season with momentum, ranking fourth all-time in passing yards through eight games behind Patrick Mahomes, Andrew Luck and Cam Newton.

Although more than a year has gone by without Mullens starting another NFL game, he believes he is now a better player.

“I just feel -- not like a veteran -- but I feel like I’ve been in it for a while,” Mullens told NBC Sports Bay Area. “I feel very comfortable, just being able to take in all the information and handle information, being able to process and know where to go with the ball.

“I don’t feel like a new guy anymore. So that’s cool to be able to just know the offense, command the offense, connect with your teammates and do a lot of different things you might not feel comfortable doing when you’re the new guy.”

Mullens won the backup job at the end of training camp over C.J. Beathard, but he has yet to throw a pass this season behind Jimmy Garoppolo. Wide receivers Emmanuel Sanders and Dante Pettis are the only 49ers other than Garoppolo to attempt passes this season.

Mullens entered the NFL in 2017 as an undrafted rookie from Southern Mississippi. He was cut at the beginning of his first two seasons but remained with the 49ers’ practice squad.

After Garoppolo sustained a season-ending knee injury in Week 3, Mullens was promoted to the No. 2 spot on the depth chart behind Beathard. After Beathard struggled while taking a physical punishment, Mullens got his chance in the middle of the season.

He was prepared for his opportunity, and never gave coach Kyle Shanahan any reason to take him out of the lineup.

Mullens, known as a detailed worker, takes the same approach to be ready for his next opportunity, he said. He has a specific process he goes through at the beginning of every week.

“You tell yourself every week, ‘You’re starting this week; prepare like you’re the starter,’” Mullens said. “So I have a pretty detailed and specific routine, just playing the game in my mind and seeing what’s going to happen and walking through plays.

“That’s the biggest part because you don’t get reps. So you have to walk through the plays in your mind and physically to be able to feel what it’s going to feel like on game day. So you’re always staying ready and doing as much as you can to prepare.”

Three weeks ago, Reggie Bush posted a video on social media of his former New Orleans Saints teammate Drew Brees in an otherwise empty practice facility walking through some plays. Mullens said he does something very similar.

“That video is pretty cool,” Mullens said. “It shows why he’s been great for so long. I think that’s something quarterbacks try to do is see things before they happen. Drew has been the best at that.”

Mullens added, “I’m trying to get used to what each play is going to feel like and going through your progressions and really just being able to step in and command the offense whenever that time comes.”

Mullens stands next to 49ers quarterbacks coach Shane Day on the sideline during games. Day tells the backup quarterbacks to "play the play as much as you can in your head.” Mullens will know Shanahan's play call and what the progression is designed to be against certain defenses. Then, he will read the defense in real time and visualize where he would be going with the football.

Mullens provides Garoppolo with as much assistance as possible. And just watching Garoppolo this season has been beneficial for Mullens, he said.

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Garoppolo started all 16 games this season and put together one of the best statistical seasons in club history. His 69.1 completion percentage was third all-time among those with 10 or more starts in franchise history. Garoppolo threw for 3,978 yards, ranking behind only Jeff Garcia and Steve Young (twice) among 49ers quarterbacks.

“He’s so consistent,” Mullens said of Garoppolo. “The best quarterbacks and football players are consistent. And he’s just consistently making big-time plays and handling big environments. The Saints and Seahawks are his most two efficient games and that’s in the two hardest environments.

“He thrives off the big moment, and that’s what you look for in a quarterback. So it’s awesome, and I’ve learned a lot from observing him and seeing how to be consistent as a quarterback.”