SANTA CLARA, Calif. (AP) DeForest Buckner is feeling pretty comfortable during his first NFL training camp.

The San Francisco 49ers' first-round pick is learning the NFL game from his former college coach, Chip Kelly. He's playing next to one of his best friends and former Oregon teammates Arik Armstead. Jerry Azzinaro, Buckner's college position coach, joined Kelly with San Francisco.

The familiar faces are helping Buckner's play stand out. The seventh-overall pick performed well enough during practice to earn time with the starters during the first week of training camp. In the early going, he's living up to the billing as one of the most highly-touted prospects in the recent NFL draft.

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''(Buckner) worked his way from the third string all the way up to the first string,'' defensive coordinator Jim O'Neil said. ''We didn't give him anything. He had to earn it. So, he earned our respect. He earned the players' respect. I think all of our guys know, we don't care where you were drafted. You're going to have to earn it. Nothing is going to be given to you and he's done a nice job.''

Buckner will try to improve the defense that ranked 29th in the NFL in 2015, when the team finished 5-11 and fired coach Jim Tomsula after one season. The 6-foot-7, 300-pound defensive end has been difficult to block for offensive linemen during the first six training camp practices.

''He's a good player,'' Armstead said of his Oregon teammate. ''I think he showed that in college, came out here day one, is competing and making plays with the ones, with the twos. And I think he earned that to be able to get some reps.''

The 49ers lost a number of key veterans on defense in recent seasons, including former All-Pros Patrick Willis, Justin Smith and Aldon Smith. Alongside Armstead, a first-round pick in 2015, the 49ers are hoping Buckner turns into a Pro-Bowl caliber player to help rebuild a defense that reached three straight NFC Championship games from 2011 to 2013.

Buckner and Armstead spent some of their time off before training camp working out on the sandy beaches of Hawaii. With them was Seattle Pro-Bowl defensive lineman Michael Bennett, who had 10 sacks last season and imparted veteran wisdom to the first- and second-year 49ers.

''He definitely taught me and Arik a bunch,'' Bucker said. ''Even though he plays for the Seahawks, he was really good help, helping us on our pass rush game and everything.''

The work appears to be paying off for the seventh-overall pick.

Buckner was a key player in Kelly's final recruiting class in Oregon. He joined the Ducks in 2012, a season before Kelly left to coach the Philadelphia Eagles. Back then, Buckner was a 260-pound pass rusher.

''He's grown. That's the biggest thing,'' Kelly said. ''When we first got him, he actually lined up when we first got him at Oregon at outside linebacker for us and then eventually grew into a 305-310 pound defensive lineman. So, just how big he is physically and just that growth and I still think he's got a little bit more to grow.''