Raddysh, 22, has collected eight goals and 18 assists for 26 points in 54 AHL games with the Rockford IceHogs this season, showing increases in all three offensive categories from his rookie year in 2017-18.
The Toronto native picked up 22 points (five goals, 17 assists) in 66 games with Rockford a year ago, playing on an AHL contract. He signed as a free agent with the Blackhawks on May 21, 2018.
Holland, 28, has tallied 20 goals and 29 assists for 49 points in 52 AHL games with the Hartford Wolf Pack this season, tied for sixth in the AHL in scoring.
The ninth-year pro from Toronto has skated in 231 career AHL contests, recording 88 goals and 118 assists for 206 points.
A first-round choice by Anaheim in the 2009 NHL Draft, Holland has skated in 266 NHL games with the Rangers, Coyotes, Maple Leafs and Ducks, totaling 36 goals and 49 assists for 85 points.