The Ducks recalled center Richard Rakell from the AHL on Monday.
Goalie Viktor Fasth also returned to Anaheim for treatment on his lower-body injury.
Koivu was knocked unconscious on a hit by Columbus' Brandon Dubinsky, who was ejected from Anaheim's 4-3 victory over the Blue Jackets. Koivu must be tested and evaluated before he is allowed to return to the Ducks, per NHL protocol.
The 20-year-old Rakell played in four games with Anaheim last season.
Anaheim is 2-2 on its eight-game road trip, which continues Tuesday in Philadelphia.
Copyright 2014 Associated Press. All rights reserved. This material may not be published, broadcast, rewritten, or redistributed.