SALT LAKE CITY — Visibly frustrated, following a painful Game 5 playoff exit to the Houston Rockets, Donovan Mitchell’s facial expression couldn’t hide his mood at the postgame press conference.

After going 4-for-22 from the field during the 100-93 loss on April 24, the Utah Jazz star guard delivered a rare, two-word response when asked about his approach to the offseason.

“Better shape,” Mitchell declared. “I’ll just leave it at that.”

Despite scoring a sophomore-best 23.8 points, while helping the Jazz finish the regular season 50-32, the former Louisville star posted the worst playoff Player Efficiency Rating (6.9) by a player with a 30% usage rate since at least 1973 — per Basketball Reference.

His response? Work harder.

After his runner-up Rookie of the Year campaign in 2017-18, Mitchell was sidelined for the majority of the 2018 summer, until late July, while recovering from a left foot injury he suffered in Utah’s playoff run.

This summer, though, he kicked things off much sooner as early as June with workouts in New York with famed trainer Chris Brickley and with new backcourt mate Mike Conley Jr. in Los Angeles with skills trainer Chris Johnson, even before his Memphis-to-Utah trade became official.

Whether it was returning to his alma mater, the University of Louisville, traveling back and forth to Salt Lake City or going overseas for a lengthy Adidas trip for his first signature sneaker, there has been one common theme in all of Mitchell’s travels: hard work.

Jazz assistant strength and conditioning coach Jasper Bibbs even accompanied Mitchell for the Adidas tour, where he was still pushed to stay in shape despite his other business obligations. Mitchell was lifting heavier weights and not fatiguing as fast, with a stronger mental focus during workouts that has improved with maturity, per sources.

Now, he’s representing Team USA on the FIBA World Cup stage in China before returning to Utah for training camp in preparation for Year 3 with the Jazz. On Wednesday, Mitchell and Team USA were upset by Jazz teammate Rudy Gobert and France in the World Cup quarterfinals. Mitchell had a game-high 29 points with six rebounds, four assists and two steals, while Gobert added 21 points, 16 rebounds, three blocks, two assists and a steal.

Sources close to Mitchell say he’s “laser focused” and has even switched his diet briefly, notably drinking more water, as he’s become disciplined with time. He recently celebrated his 23rd birthday with 10 points in Team USA’s 69-53 win over Greece on Sept. 7.

This year’s Jazz roster will look much different than during Mitchell’s first two seasons, with the additions of Conley, Bojan Bogdanovic, Emmanuel Mudiay, Ed Davis and Jeff Green. However, there is still two-time Defensive Player of the Year Rudy Gobert patrolling the paint as well as do-it-all role players Joe Ingles and Royce O’Neale in the lineup. Backup guard Dante Exum is set to return from an injury-riddled season, plus Georges Niang and Tony Bradley are back.

After reaching the playoffs for three consecutive seasons — the first time since 2009-10 — the goal is now to capture the Larry O’Brien Trophy, but they will need Mitchell to take that leap to have a legitimate shot.

Conditioning won’t be an issue for Mitchell this time around, now that he’ll have a lock in on the details of the game to become more efficient, such as spacing, decision-making and shot selection. If he does, he won’t have to worry about addressing the media with a stale face following another first-round playoff exit.

Actually, playing basketball again this summer should play a significant role in that.

“A lot of it for me is I just missed the game of basketball,” Mitchell told the Deseret News in August during Team USA training camp in Las Vegas. “So, just going out there and hooping every day, it’s been a lot of fun, but also I wanted to take care of my body as well.

“Being able to take days off, which was tough for me at the beginning, but now I’m starting to figure it out and obviously playing with guys like Kemba (Walker), Khris Middleton, Harrison Barnes, Thad Young … learning how to take care of your body, learning different vets that I don’t normally learn from during the season.”