Hiller returned from playing in the All-Star Game Jan. 30 in Raleigh, N.C. and began feeling lightheaded and slow to react while allowing three goals on 10 shots in the opening period of a 4-3 loss Feb. 2 against visiting San Jose. He sat out the next four and returned to shut out Edmonton, 4-0, on Feb. 13, but the symptoms reappeared and he sat out the next 15.
The Ducks, who began the day in eighth place in the Western Conference standings, play Wednesday in Dallas, then travel to Nashville for a game Thursday against the Predators. They conclude their three-game road trip Saturday in Chicago.
Hiller is 26-16-3 this season with a 2.50 goals-against average and .925 save percentage in 48 games, and is expected to start Thursday.
Dan Arritt covers the Ducks for ESPNLosAngeles.com. Information from The Associated Press was used in this report.