The 24-year-old Maatta had 14 points (one goal, 13 assists) and 116 blocked shots in 60 games for Pittsburgh this past season. He also logged 97 hits. Maatta is a two-time Stanley Cup champion with the Penguins who has played in 69 career playoff games, including all 25 postseason contests in Pittsburgh's championship season of 2016-'17.
Maatta's contract carries an average annual value of just shy of $4.1 million and runs through the 2021-'22 season.
Kahun had 37 points (13 goals, 24 assists) for the Blackhawks in 82 games last season, his first in the NHL.