As the Patriots players stream onto the practice field for training camp sessions, they generally do so in small groups of two or three, often players from the same position walking and chatting before they get down to the day’s business.

And nearly every day since camp began, when Tedy Bruschi walks onto the field, he’s accompanied by one of his newest teammates: Oscar Lua.

The seventh-round draft pick has undeniably chosen wisely when it comes to his mentor; Bruschi has long been the heart and soul of the Patriots defense, a high-motor player whose fan-given nickname is “full tilt, full time” and who has tremendous respect in the locker room.

“Tedy has been really great,” Lua said recently. “He’s taken me under his wing. He told me if I have a question, ask him. He’s been letting me tag along.”

Lua and Bruschi are nearly identical physically: the USC product is listed at 6-foot-1, 240 pounds, while Bruschi is 6-1, 247. That size has been just about perfect for Bruschi in a dozen years with the Patriots; Lua must be hoping it does the same for him.

Lua’s resumé is mostly underwhelming — after an All-West career at Indio (Calif.) High, he played as a true freshman with the Trojans as a backup middle linebacker, and was a medical redshirt due to a knee injury the next year.

In 2004, he remained a backup, but became a key special-teams contributor on USC’s national championship-winning team. As a junior, his only year as a starter, he led the team in tackles, but as a senior, he was a backup once again.

But Pierre Woods was similarly unheralded when he was an undrafted rookie last year, and he made the 53-man roster and will likely play a reserve role this season.

Perhaps because he is and has always been an underdog — he was labeled an “overachiever” by some scouts before the draft — Lua has quickly gained a soft spot in the hearts of many fans, who discuss his chances of making the 53-man roster on chat boards.

Middle linebacker might be the toughest position on Bill Belichick’s defense. Players there are responsible for a number of things, including often making the play calls, being able to blitz, be a run stopper, drop back in pass coverage, and make subtle shifts — sometimes on the fly.

“I feel pretty good,” about how training camp is going, Lua said. “I’m still a far cry away from being at the level I want to be at. I understand a lot of it for the most part, and I’m comfortable with the learning curve, so I’m happy with it.”

He may be a New England newbie, but Lua knows that the best way to stick around in Foxboro is to “come in, find your role. Find something you’re good at.”

Lua has been lining up in the middle for the second-team defense, where he is calling the plays, and is continuing as a special-teamer. As a linebacker, it appears that his strength is against the run.

On Friday night, he played in his first NFL exhibition game. Though he admitted that he would be nervous before kickoff, Lua showed well against Tampa Bay, credited with five solo tackles.

While he has nestled himself comfortably under Bruschi’s wing, Lua, who started playing football at 11 years old and was also a standout high school baseball player, grew up idolizing another of his Patriots’ teammates, Junior Seau.

Seau is a Southern California legend of Samoan descent; Lua is also a Southern California native of Samoan heritage.

When he was first drafted in April, Seau’s return to the Patriots after a season-ending broken arm last November wasn’t a certainty; now Lua is in meetings with Seau every day.

He still gets a bit awestruck at times, watching the 18-year veteran, 12-time Pro Bowler and sure-fire Hall of Famer on the same field with him.

“I think a lot of guys probably admire him,” Lua said. “It’s perfect that I get to play with him. I’ve learned professionalism from him: he comes in earlier than the any of the linebackers, lifts, watches film, then starts studying. From Junior I’m learning how to be a football player.”

smanza@projo.com