TUALATIN - Portland Trail Blazers rookie Zach Collins is soaking up as much as he can during his first NBA training camp, pushing through three-hour practice sessions, exhaustive weight work and even trips to the grocery store.

It's been a week of two-a-days and Whole Foods for the 19-year-old 7-footer.

The acclimation process for an NBA rookie can include a little bit of everything and the inquisitive Collins is trying to learn as much as he can on the court while he figures out how to best take care of himself off it.

That's why Collins and Blazers team nutritionist Michelle Tegenkamp went grocery shopping this week. The rookie big man got a crash course in which brands of organic foods would best fuel his body as he tries to put on weight and build an NBA-ready frame.

"I just try to eat as much as I can without getting sick," he said with a smile. "Just a lot of organic stuff. That's basically the big thing. They can tell you to eat a lot but you're not supposed to eat bad stuff."

On the court, he has gone through two full days of official practices after missing the opening day of training camp with a concussion. It's been a whirlwind 96 hours of NBA life, but Collins has been making the transition into the professional basketball world for nearly two months.

It started in summer league, where Collins struggled in two games, got injured in practice and was ruled out before finishing the third game. After his frustrating, shortened week at summer league in July, Collins returned to Las Vegas in early September. He participated in Tim Grgurich's famous offseason skills camp, where both he and Blazers coaches said he looked and felt much more comfortable than he had six weeks prior.

That's the theme for Collins' summer: He's been in the gym, gaining comfort each day. Back in Portland that process has meant long days at the practice facility.

"We had a lot of guys here for like three weeks (in September)," Collins said. "So we got to get up and down, played pick-up every day. We were going really hard, conditioning twice a week, lifting before every pick-up, getting shots up after (and) working out twice a day."

On most days, Collins would follow pick-up games by drilling the playbook for 20 minutes with an assistant coach on an adjacent court. Other days he would play 3-on-3 prior to the full squad pick-up games to increase his familiarity with the offensive actions in Terry Stotts' playbook.

The expectations for Collins are admittedly tepid. The Blazers front office has repeatedly touted the No. 10 overall pick as part of the future, the subtext of which is that he isn't a major part of the present. There are veterans ahead of him on the depth chart and the Blazers will be patient with his development. And Collins isn't putting any outward pressure on himself to be a day one contributor.

"I don't really have a set number of goals," he said, "But I know for me (it's) consistently, every day just get better and improve."

His teammates have been impressed with his skill level, willingness to take instruction and intensity.

"One thing that I like about both our rookies is they're not shy," Damian Lillard said. "They don't hide it. They get excited and they really care. Zach had a few times yesterday in practice where I just heard him screaming when he won a drill. He's not afraid to show it and he cares."

When the media was let into the gym on Thursday, Collins was engaged in a three-point shooting competition with Archie Goodwin and Al-Farouq Aminu. As he let go of his winning corner jumper, he turned his back to the rim.

"Ball game," he said to Aminu and Goodwin as his shot swished clean.

Collins' competitive nature has also landed him on the other end of the competitions. The Blazers ring a bell mounted on the wall at the practice facility for a variety of positive plays. Collins has already earned three rings for challenging shots at the rim only to end with his teammate dunking directly on him.

There is a steep learning curve in the opening days of training camp, particularly on a team returning 12 players who are familiar with the system. Collins said the assistant coaches have been extremely helpful making sure he's doing things the right way.

"For a rookie it helps a lot," he said. "Because even when you don't think you messed up (the assistant coaches) will let you know before coach gets on you."

The dunks, the weights and the organic groceries are all part of the rookie learning curve, a wide ranging acclimation process that Collins is embracing in the early stages of training camp.

"I think I've gotten a lot better going through one (practice) and today I played even better than I did yesterday," Collins said on Thursday, two official practice days into his NBA journey. "I'm just getting more and more comfortable."

-- Mike Richman

mrichman@oregonian.com

@mikegrich