De Haan, 28, is the headliner return for Chicago, as he'll provide reinforcement for a Blackhawks defensive group that struggled mightily in 2018-'19. He had one goal and 13 assists in 74 games for the Hurricanes last season, and his contract has three years remaining on it at an average annual value of 4.55 million.
Saarela, 22, has appeared in one NHL game. He had 30 goals and 24 assists in 69 regular-season games for the Charlotte Checkers of the AHL last season. He helped the Checkers win the Cup Cup championship. Saarela was selected by the Rangers in the third round of the 2015 draft. His contract carries an average annual value of $902,500 through the end of the 2019-'20 season.
Forsberg was with the Rockford Icehogs of the AHL all last season. He was 10-16-4 with a 2.97 goals against average and .908 save percentage for the Blackhawks in 2017-'18.
Forsling had three goals and six assists in 43 games for Chicago last season.