He was still at the University of Maryland Shock Trauma Center as of Monday afternoon, but hopes to be discharged later in the day, according to multiple reports.
Clyde Christensen, the Colts' quarterback coach, called plays Sunday against the Ravens, who defeated Indianapolis 24-9.
Indy's only points came on three field goals by Adam Vinatieri, from 47, 52 and 26 yards. Luck completed 28-of-54 passes for 288 yards. It was the most attempts by a rookie in a playoff game.
Arians served as interim coach for 12 games this season, going 9-3, when Colts head coach Chuck Pagano was undergoing chemotherapy treatment for leukemia.
Arians became dizzy Sunday morning, a source told ESPN. After running tests, doctors think he may have a virus or inner ear infection.
Arians says he feels he could have left to coach the game but doctors would not let him, the source said.
Information from ESPN NFL Insider Adam Schefter and The Associated Press was used in this report.