Publicist Arnold Robinson Saturday said one unidentified member of Thornton's band, the Boxmasters, and several members of the band's crew, have the flu, CNN said.
The cancellation of the band's remaining concerts in Montreal and London, Ontario, came in the wake of a controversial radio interview by Thornton on Canadian Broadcasting Corp. radio.
Thornton, 53, told CBC host Jian Ghomeshi Wednesday that he views Canadian audiences as "mashed potatoes with no gravy."
"We tend to play places where people throw things at each other and here they just sort of sit there," Thornton told the CBC.
CNN said in apparent reaction to Thornton's radio comments, the Boxmasters were booed Thursday in Toronto while opening for the pop band Hanson.