SANTA CLARA, Calif. -- After an up-and-down rookie year that saw him start five games, lead the San Francisco 49ers to their first win of the season and then be replaced by Jimmy Garoppolo, quarterback C.J. Beathard returned to his home state of Tennessee.

Niners tight end George Kittle, receiver Trent Taylor and a handful of other NFL players joined Beathard in Nashville for offseason workouts. Beathard, who is from Franklin, Tennessee, about 20 miles south of Nashville, hosted the workouts at Battle Ground Academy, a school that Kittle said has a larger campus than some colleges and boasts an indoor practice facility for the football team.

While Garoppolo-mania swept over the San Francisco Bay Area, Beathard doesn't lack for celebrity status when he returns home.

"Everyone knows who C.J. is down there," Kittle said, laughing. "At his high school, everyone knows who he is. He's a rock star."

Now, the Niners are turning to Beathard in hopes he can make the offense sing after Garoppolo's season-ending knee injury. While there was no shortage of outside clamoring for the 49ers to trade for a quarterback or to coax someone like Jay Cutler out of retirement, the Niners and coach Kyle Shanahan stood steadfast in their belief in Beathard.

That faith is rooted in how Beathard handled his first real NFL experience as a rookie. Since the Niners traded up to spend the 104th pick in the 2017 NFL draft on him, Beathard has impressed coaches, teammates and personnel types with his intelligence and his toughness after being tossed into what Shanahan regularly refers to as "a very tough situation."

The Niners drafted Beathard with the idea he would sit behind veteran Brian Hoyer and learn Shanahan's system without having to play other than mop-up duty. Those plans were scrapped five games and one quarter into the season, as Beathard replaced a struggling Hoyer in the second quarter of a Week 6 loss to the Washington Redskins.

Surrounded by a supporting cast that had been dramatically altered in the offseason and featured little in the way of game-breakers at the skill positions and a patchwork offensive line, Beathard cut it loose. He threw for 245 yards with a touchdown and an interception in little more than two quarters of play and nearly led the Niners to a comeback win.

From there, things got quite a bit more difficult, however. Beathard's supporting cast continued to suffer from injuries, and in many cases, Beathard found himself an easy target in the pocket for defenses unafraid he could make them pay for dialing up pressures. In five starts, Beathard took 19 sacks and was contacted 53 times by defenders.

Despite those brutal outings that often left him visibly bruised, Beathard kept coming back for more, earning praise for his toughness, even if his production wasn't much to celebrate. He finished with 1,430 passing yards, four touchdowns and six interceptions while completing 55 percent of his passes for a passer rating of 69.2 -- before Garoppolo was handed the reins in Week 13.

After Garoppolo took over, Shanahan said Beathard handled it like a pro, even if Beathard expressed his disappointment behind closed doors.

"He got the crap kicked out of him a bunch and never flinched, didn't change who he was, still wanted to be in there and was disappointed when we took him out and put Jimmy in, because that's the competitor he is and he believes he can do it," Shanahan said. "So, it was hard for him at first. But he was very supportive. He saw how well Jimmy played, and he keeps it real, and he understood it. He's worked. He hasn't sat back and just been happy with being a backup.

"I think C.J. has very high expectations for himself. He sees himself being a starter one day, and he's going to get an opportunity now. This isn't something that has just surprised him. He's been waiting for this moment, and that's why I know he'll take advantage of it."

Still, while Beathard didn't get much help last year, many of his struggles were things commonly seen in rookie quarterbacks. Most notably, Beathard was a bit slow to get through progressions, and though he actually got the ball out quicker than the league average quarterback (he averaged 2.42 seconds before passing), he often was quick to check down.

According to Pro Football Focus, Beathard targeted running backs on 32.1 percent of his passes, the most of any quarterback in the past decade. When throwing to running backs, Beathard let it fly after just 2.36 seconds, well below the league average of 2.5 seconds on such passes. As such, Beathard struggled with intermediate accuracy, an area Garoppolo excelled. Beathard completed just 48.8 percent of his passes traveling between 10 and 25 yards in the air, which ranked 41st in the league.

Of course, many of those numbers are fairly common for rookie quarterbacks adjusting to the speed of the NFL. Beathard believes that things will slow down for him now that he has a deeper understanding of the intricacies of Shanahan's offense or, as Shanahan likes to call it, the "whys" of the scheme.

"It's Year 2 for me in this offense," Beathard said. "With any extra time doing something, the better you get at it. I definitely understand more of the whys. Why certain things happen, why this guy we think will be open, why we attack certain things versus certain coverages and stuff like that.

"Having gone out there and played in five NFL games, there's nothing you can do to simulate those reps in practice. The only way you can do it is by going out there and actually getting those game-time reps. Just being another year under the system and Kyle's offense helps a ton, just the knowledge of the offense, getting through progressions quicker and all of that kind of stuff."

On Wednesday, Kittle, who played with Beathard at Iowa, recalled the moment he knew Beathard had NFL ability. At the 2015 TaxSlayer Bowl, Tennessee jumped to a 28-0 over the Hawkeyes as Beathard split time with Jake Rudock. Iowa would go on to lose 45-28, but the Hawkeyes enjoyed most of their offensive success with Beathard under center.

This week, Kittle already has seen that same resolve in Beathard and has joined a chorus of teammates offering support for the second-year quarterback.

"He's a guy that you just have faith in him the second he steps on the field, just his attitude, and he commands the huddle pretty well," Kittle said. "As soon as he's out there, it's like, 'All right, this is the guy that we want to be out there.'"