SANTA CLARA -- The only legitimate concern about defensive end Nick Bosa as he moved onto the 2019 NFL Draft from his three seasons at Ohio State was his ability to remain on the field.

As a rookie, the 49ers cannot keep him off the field.

Bosa, the No. 2 overall pick in the draft, has proven to be a reliable every-down player who rarely comes off the field at a position where it is common for defensive linemen to constantly shuttle on and off the field.

“I love it,” Bosa said. “In college, I rotated a lot. And it frustrated me to be out for important plays of the game. And now I get to be an important part of the defense at all times. So it’s a lot of fun.”

Bosa was selected Tuesday as one of four 49ers players to be a starter on the NFC team in the Pro Bowl.

He becomes the first 49ers rookie to be selected on the original vote since Patrick Willis in 2007. Safety Eric Reid was added to the Pro Bowl as a replacement when he was a rookie in 2013.

Bosa has played 662 snaps through 14 games this season, matching the play time of fellow D-lineman Arik Armstead. DeForest Buckner leads the team’s defensive linemen with 694 snaps.

Bosa appeared in just three games in his final college season due to a core muscle injury. He sustained a torn ACL in high school. He missed most of the 49ers' offseason program with a hamstring injury, then did not play in the preseason due to a high-ankle sprain.

The 49ers eased Bosa into the action to open the regular season. He played fewer than 40 snaps in five of the 49ers’ first six games of the seasons.

Now, as he’s gained experienced and the 49ers’ depth has been weakened by injuries, Bosa rarely comes off the field. He has averaged 59 snaps per game over the past six weeks.

Coach Kyle Shanahan recognizes the 49ers have relied a lot more on Bosa, Buckner and Armstead than they had originally planned due to injuries to Ronald Blair, Dee Ford, D.J. Jones and Damontre Moore.

“The more reps people take they can’t go as hard for every time they’re in,” Shanahan said. “I think guys do wear down a little bit with that. It’s something you fully expect this time of year, as the year goes, but it does add up. We do have some more guys coming back, but this is what happens when these injuries happen.

“The more you’re out there, the more you wear down. But it’s time to go, there’s not a lot of time left anyways.”

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Bosa ranks second on the 49ers -- behind Armstead -- with nine sacks. He leads the 49ers with 16 tackles for loss to go along with one interception and three passes defensed. He has started each of the past 12 games.

“I always want to be out on every play, then I realized sometimes it would be better for me to take a couple plays off early in the game,” Bosa said. “I’ll be out there whenever our team needs me.

“I definitely don’t pace myself. Maybe I need to learn how to. But I just go hard every play. It might end up biting me in the end.”