Marinaccio, a Bemidji State recruit, had two goals and six assists in 16 games for Cedar Rapids but was a minus-9. He had six goals and nine points in 14 games this season for Chicago.
Olsson is two years younger than Marinaccio at 18, and posted two goals and three assists in 22 games for Lincoln. The Billerica, Mass., resident and Northeastern University commit, also was plus-one.
He brings size to the table at 6-foot-4 and 200 pounds. Olsson was No. 121 among North American skaters in NHL Central Scouting's midterm rankings of draft-eligible players.
With the trade of Marinaccio, who is Canadian, the RoughRiders have one open import spot available on their roster.