Rutherford adds an announcement could come later this week.
O’Reilly will replace Alex Pietrangelo, who wore the “C” for four years but left the Blues in free agency to join the Vegas Golden Knights.
“He will make a great captain. Good luck to him, no doubt he is the right choice,” Pietrangelo told Rutherford.
The 29-year-old O’Reilly is entering his third season with the Blues and won the Conn Smythe and Selke Trophies in the club’s Stanley Cup-winning 2018-19 season. Last season he placed third in both Selke and Lady Byng trophy voting.
“It would be an honour if it does happen,” O’Reilly said in November when asked about the possibility of being named captain in an interview on Sirus XM.