He had an 8-16=24 stat line to his name through 36 games playing in the Allsvenskan League in 2013-14. He had just recently celebrated his 18th birthday.
Now, he's all of that, plus a first-round draft pick of the Boston Bruins, having been selected 25th overall in Philadelphia on June 27.
Being in Philly was his first time in the United States. On Monday night, it marked another first for Pastrnak, as he made his first trip to Boston in advance of the Bruins' annual development camp.
On-ice sessions for Pastrnak and the rest of the prospects begin Wednesday, July 9, at Ristuccia Arena in Wilmington, Mass. and are open to the public (check out BostonBruins.com for the full schedule).
After a long day of travel from Prague on Monday - consisting of a nine-hour flight to JFK International Airport in New York and a connecting flight to Boston - he didn't show an ounce of fatigue as he arrived to the baggage claim at Logan Airport, clad in his Bruins' polo and draft hat with the Spoked-B.
Always smiling, Pastrnak dismissed the 'positive' of having Tuesday to rest before camp kicks off on Wednesday. "It's all mental!" he said, of any jet lag.
The only worry he had was that his bag had not made the journey with him. But then the duffel bag he received from the Bruins at the draft, outfitted in Spoked-B embroidery, made its way around the conveyor belt. All clear.
Pastrnak had been on a whirlwind ride for the past week and a half, and his emotions hadn't changed since the night he was drafted.
"Unbelievable" was his word of choice that night. "I was getting nervous after every pick more and more and I’m really proud that Boston believed in me and they picked me. They’re a good organization and great people," he had said after being selected by the Bruins.
So, have those emotions subsided yet? Not quite.
"Still the same," Pastrank said on Monday in Boston. "I feel really good and still so happy."
Having only known English for a couple of years, he's still not completely comfortable doing interviews, especially on-camera. But his persona goes far beyond his words.
While the on-ice product is ultimately what matters - and Pastrnak has established himself as a right winger with solid play along the boards, grit and a strong shot, with plenty of room to grow - his optimistic personality certainly shines through.
"He competes and he’s got skill and we thought we needed some more skill. He handles the puck real well, and he protects the puck real well," Bruins Director of Amateur Scouting Keith Gretzky said after he was drafted. "And he’s full of energy. You just, you gravitate to him."
General Manager Peter Chiarelli had the same takeaways on the forward, starting when the B's brass first met him and had dinner with him prior to the draft.
"He looks up to [David] Krejci. All those young Czech players look up to Krejci and he certainly is one of them. He's got a real good personality," Chiarelli said, from the draft floor after the first round.
"Have you met him yet? He's a real energetic kid, enthusiastic, and loves to play, and he respects it as a profession. I really like the kid's personality and I like the way he plays."
Pastrnak knows he needs to get stronger, and development camp will point him in the right direction as he continues to develop his pro game in the Bruins' organization.
The off-ice components are just as meaningful, and with the forward's work ethic, he'll certainly take in all that the camp has to offer. He wants to make the Bruins proud.
Now, just as he moved away from home to Sweden when he was young, he's embarking on a new adventure. For the beginning of July, that new adventure takes him to Boston.
"It's the first time [in Boston] - it was a long flight but I was looking forward to getting here, and now that I'm already here, I've got to enjoy it," said Pastrnak.
As he walked through Logan Airport carting his bags and his skates, a view of the Boston skyline could be seen through the windows.
"This looks just like my town," he joked with a smile, as downtown Boston was pointed out to him.
His hometown of Havířov is just about on the border of the Czech Republic and Poland, and less than an hour drive from Slovakia. With a population of around 77,000, compared to Boston's roughly 637,000, and not many skyscrapers, it was an enticing sight for the newest member of the Black & Gold, even if he had seen bigger cities before.
With a new city, new organization and new 'teammates' for the week whom he's never met, Pastrnak was in for a completely new experience.
He was happy to learn that his new roommate was from Sweden, fellow 2014 draftee Emil Johansson. If he has any questions, he can also take solace in second year campers from Sweden, Linus Arnesson and Anton Blidh, along with Slovakia native Peter Cehlarik, the only other prospect Pastrnak is familiar with as he begins camp.
Outside of Pastrnak's comfort zone, he's still learning what it means to be a part of Boston and the Bruins, and part of that new education means knowing the Boston-New York sports rivalry.
In the Czech Republic, a hat with a NY Yankees logo is just a hat. After being drafted, Pastrnak quickly learned to rock a Red Sox - and only a Red Sox - hat, for the Boston faithful.
But beyond the nuances of learning about a new place and its loyalties, the newest member of the Bruins' organization is just excited for the whole process to begin.
"Exciting, very much. I'm not even tired after that [travel]," said Pastrnak. "I'm just really looking forward to being on the ice and in practices, and meeting the guys. It's going be fun."
As David Krejci would say (in Czech), Hodně štěstí!