Pastrnak, 18, is a right-handed shooting prospect who has spent the majority of his time on the right wing. He was selected with the No. 34 overall selection in the 2013 KHL Draft by the Severstal Cherepovets but opted to remain with Södertälje of the Swedish league Allsvenskan. Pastrnak has spent several years as a member of Södertälje's organization, splitting time between the major club and its related minor clubs. He registered 24 points (eight goals and 16 assists) in 36 games with Södertälje last season.
Listed at 6'0, 168 pounds, Pastrnak finished the year ranked as the No. 33 overall prospect in the 2014 NHL Draft by the ISS. Described as an energetic offensive force, Pastrnak is praised for his creativity and his qualities while playing with the puck:
Pastrnak shows the potential to be an offensive dynamo, couldn't find his rhythm with Czech Republic at the U18s but produced plenty of scoring chances. Absolutely elusive on the puck and shows dominating separation speed with agility to skate end-to-end and gain the offensive zone. Incredibly shifty and dynamic on the puck, shows good offensive tools. Possesses that special ability to keep defenders on their heels with his versatile offensive weapons and relentless motor. Despite an average performance at the U18s for his standards, he proved his game-breaking ability and mentality with Sodertalje in Allsvenskan competing against men. Possesses a raw frame with much room for physical development to strengthen his overall game.