Sundin may be a bit under the radar. He has not gotten a ton of attention for international teams or play in his time. His lone international appearance was at the U19 tournament in 2022–23. Most of his time the past five seasons has been working his way up through the Frolunda HC organization where he eventually made his SHL debut in 2022–23, recording zero points in 10 games.
So far, Sundin has shown a great ability to develop his game and continually work his way up the ranks in Sweden. Although his start in the highest league in the country has been underwhelming with just one assist in 28 games, it is notably a difficult league for young players to play in and a lack of offence is not surprising. He has shown an offensive touch in other leagues.
His greatest strength is his two-way and defensive play. Sundin has a good defensive IQ and is great with positioning allowing his timing and poke check to interrupt the opposition.
In 2023–24, Sundin wore an A for his time with the Frolunda J20 team, indicating he has a good presence with the team and is valued in the locker room.