Could 49ers' Nick Mullens be a starting quarterback in NFL?

SANTA CLARA - Nick Mullens just might have a future as a starting quarterback in the NFL.

Through four starts with the 49ers - one quarter of the season - Mullens, an undrafted free agent in 2017, has outproduced both Jimmy Garoppolo and C.J. Beathard.

Garoppolo, a second-round draft pick of the New England Patriots in 2014, signed a five-year, $137.5 million contract with the 49ers on Feb. 8. He started the first three games this season, completed 59.6 percent of his throws, averaged 8.07 yards per pass attempt, threw five touchdown passes and three interceptions, took 13 sacks and posted a quarterback rating of 90 before tearing his ACL.

Beathard, a third-round pick in 2017, started the next five games. He completed 60.4 percent of his throws, averaged 7.41 yards per pass attempt, threw eight touchdown passes and seven interceptions, took 18 sacks and posted a quarterback rating of 81.8 before losing his job to Mullens.

Mullens, a practice squad player until Sept. 26, has completed 64.5 of his throws, averaged 8.13 yards per pass attempt, thrown seven touchdown passes and five interceptions, taken just seven sacks and posted a quarterback rating of 91.5. Mullens’ numbers are better than Garoppolo and Beathard in just about every category.

“(Mullens) is a really good young quarterback,” Broncos head coach Vance Joseph said on a conference call. The Broncos will play the 49ers Sunday at Levi’s Stadium.

“(Mullens) has a quick release,” Joseph continued. “He has a presence about him that goes beyond his age. When you watch this guy play, you don’t see a young guy playing for the first time. You see a seasoned quarterback who is making decisions at the line of scrimmage and making every throw. If we don’t contain him, it can be a long day.”

Mullens reminds Joseph of his own quarterback, Case Keenum, an undrafted free agent in 2012. Keenum played for three teams before he signed a two-year, $36 million deal with the Broncos during free agency.

“(Keenum and Mullens) play with a true chip on their shoulders,” Joseph said. “It’s always them against the world. Nick plays that way. He plays with an edge. He gets excited after tough plays. He’s a tough guy. He bounces back from tough plays and plays on. Case is the same way. We can have games when he’s not playing his best ball, but in the most critical moments of the game, Case plays his best football. I see a lot of that same trait in Mullens.”

Mullens takes heart in Keenum’s rise to success. “Being an undrafted guy,” Mullens said, “I’ve done research on different guys’ paths and how they’ve made it, how they’ve stuck around in the NFL. (Keenum) is definitely a guy that I’ve looked at his path, see how he’s gone. He’s a great quarterback. He’s earned everything he’s gotten in his career and that’s what I respect most about him.”

Keenum’s quarterback rating this season is 85.1. Mullens has outproduced him, too.

Still, head coach Kyle Shanahan doesn’t seem sold on Mullens. “He has been in some easier situations than others,” Shanahan argued. “I think those first two games were not as challenging as the last two. I thought he played very well versus Oakland, but I knew we had a chance to (play well as a team). That doesn’t take anything away from him. He executed perfectly.

“Against the Giants, he did some good things, too. Against Tampa, I thought he took a little bit of a step back like everyone did, but I was real impressed last week versus Seattle. I knew how hard it would be for him, let alone any quarterback, not being used to (playing) there.

“He played under a lot of duress in that game, with the noise, the score, the pass rush. And he got off to a rough start in the first quarter, but I was real impressed with how he rebounded. I thought he played three quarters of pretty good football.”

Mullens finished last Sunday’s game with 414 passing yards - third most by an opposing quarterback in Seattle since Pete Carroll became the head coach of the Seahawks in 2010. Only Ben Roethlisberger and Philip Rivers have passed for more yards in Seattle the past nine seasons than Mullens.

“He played a pretty good game,” Shanahan reiterated.

Tepid praise.

In the past, Shanahan has seemed more eager to praise other quarterbacks, especially Beathard. The 49ers traded up in the draft for Beathard, and Shanahan called him “the best quarterback in the building” after Garoppolo injured his knee.

Here’s what Shanahan said about Beathard on Nov. 8 after Beathard lost the starting job: “C.J.’s story is not over. He has the ability, the toughness and the mind to be a very successful quarterback in this league.”

Here’s what Shanahan said Wednesday about Mullens’ shot to become a very successful quarterback in this league: “I don’t know. He’s got command of the offense. I think the game is not too big for him. But I’m not going to go there yet.”

Here’s what Joseph said when asked if Mullens might be a starting quarterback someday: “I think he has a chance.”