LAS VEGAS -- The first difference you notice about Allen Crabbe is the hair.

The traditional look he sported his first two seasons in the NBA is long gone, replaced by a wild high-fade Mohawk featuring frosted tips.

"It's summertime, man, you've got to change it up," he said of a look that teammates have been ribbing him for. "I like it. I think I'm going to keep it."

But the new hairstyle has overshadowed the other, more important, changes to Crabbe's appearance.

The bigger chest. The larger arms. The stronger base.

The Trail Blazers' backup shooting guard has spent the offseason reshaping his body and redefining his game in an effort to recalibrate his NBA career. Crabbe is entering the third and final year of a three-year contract he signed as a rookie, and the motivation to extend his career, coupled with the opportunity he sees as part of a rebuilding Blazers roster, has generated significant changes in his diet, workout routine and drive.

"I know it's a big year for me," Crabbe said. "It's going to be my last year under contract. And with the roster changes, there's going to be an opportunity (to play). When that opportunity comes, I don't want no excuses this year, so I'm making sure I'm doing everything I need to do to solidify a rotation spot. I just want to make sure that I'm doing everything right."

After the Blazers' season ended April 30, following a gentleman's sweep in the first round of the Western Conference playoffs against the Memphis Grizzlies, Crabbe started shifting his focus to the 2015-16 season. He decided he would stay in Portland throughout the summer to focus on basketball and avoid his native Los Angeles and its enticing summer beaches and lively night scene.

He allowed himself to take two weeks off from basketball for a little R&R. Then he dove headfirst into a summer of growth.

First up, Crabbe wanted to get stronger and reshape his body, which not only would require dedication in the weight room, but also an overhaul of his eating habits.

He cut out fast food and hired a chef to prepare healthy foods and meals appropriate for his body type. Trips to the drive thru have been replaced by home cooked meals featuring chicken and vegetables and steak and asparagus. He tried cauliflower for the first time -- and liked it. He's also mixing in regular protein shakes.

"I'm buying into eating," he said, laughing. "It's tough, but I know it's going to pay off in the long run."

As he changed his diet, Crabbe started living at the practice facility in Tualatin. Since that two-week break, he's religiously worked out three times a day, four days a week, mixing in an occasional basketball workout on Wednesday, which is supposed to be his off day.

Crabbe arrives in the morning for a basketball workout, spends the afternoon grinding away in a weightlifting session, then returns later in the evening for another round of basketball work.

He's never been a slacker. But he's also never been this dedicated.

"AC's been in the gym every day -- all summer," Tim Frazier said. "Every time I go there, he's there."

Crabbe ended the season weighing a shade below 210 pounds. In two months, he's added seven pounds and altered his frame, adding bulk to his upper body and strength to his base. His goal is to get to between 220-25 pounds before the start of training camp in October.

The new physique certainly helped Sunday night, when the Blazers defeated the Dallas Mavericks 93-80 at the Las Vegas Summer League. Crabbe finished with a game-high 24 points, making 9 of 12 shots, including 3 of 4 three-pointers. He swished catch-and-shoot threes, converted dribble-dribble pull-up jumpers and mixed in a couple driving floaters off the glass. All the while, he deftly defended multiple positions.

During his flood of basketball workouts this summer, Crabbe has worked on adding a post move to his offensive repertoire and, as always, tried to improve his dribbling. But even more, he's been laser-focused on his jump shot. He was drafted because of his shooting ability and he's earned minutes -- including nine starts last season -- in part, because of that stroke.

But Crabbe made just 30 of 85 three-pointers last season (35.3 percent), which is respectable, but not elite for someone with Crabbe's potential. So he and assistant coach Nate Tibbetts have spent countless hours this summer working through shooting drills that feature constant movement and shooting, an effort to simulate game action. Crabbe has a tendency to rush his mechanics, so the hope is that extra game-simulated shooting will calm down his shooting stroke and create more patience next season.

"I was more patient (Sunday night)," he said. "I wasn't rushing into my shot. Held my follow through instead of dropping my hand too quick. Felt like I was in a rhythm. I just want to make sure when the season comes around and I get (an) opportunity that I'm knowing down shots. That's what Portland drafted me for; I'm a really good shooter. I don't want them to feel like they made a mistake."

Crabbe is only two months and two summer league games into his summer of growth. But the early results are positive.

"I feel good out there," he said. "I feel stronger. I'm feeling a lot more comfortable on the floor. I feel like this summer league is helping me gain that confidence. Everything is paying off so far, so hopefully I can keep it up. This offseason is big for me. I want to stay in this league and I don't want there to be any reason for Portland or any other team not to want me."

--Joe Freeman | jfreeman@oregonian.com | 503-294-5183 | @BlazerFreeman