The 21-year-old Puustinen was one of Pittsburgh's seventh-round (203rd overall) draft picks in the 2019 NHL Draft. His contract will begin at the start of the 2021-22 campaign.
"Valtteri is a skilled forward with a great shot who utilizes his speed to play the style of game that we want to play here in Pittsburgh," said assistant general manager Patrik Allvin. "He's really matured as a player over the last couple of years playing with HPK and the Finnish national team, which is really exciting for us."
The 5-foot-9, 183-pound Puustinen spent the 2020-21 season with HPK of Liiga, Finland's top professional league, recording 41 points (21G-20A) in 51 games. His 21 goals led all HPK skaters and were tied for eighth in the league, while his 41 points were second-most on HPK. He was one of just four skaters in Liiga to record 20 or more goals and assists this season.
Puustinen has spent the last three seasons with HPK, registering 94 points (48G-46A) in 152 games. Puustinen helped HPK win the Liiga Championship in 2019, notching five points (2G-3A) in 16 playoff games, where he was teammates with current Penguins' prospects Niclas Almari, Emil Larmi and Jesper Lindgren.
A native of Kuopio, Finland, Puustinen won a gold medal with Team Finland at the 2019 IIHF World Junior Championships, where he suited up for six games and had three assists. He is currently at Team Finland's 2021 World Championship camp, vying for a spot on the team.
