According to Rosenthal, the Royals are expected to receive a catcher in return.
Hendriks started the 2014 season with the Blue Jays before being traded to Kansas City in July for third baseman Danny Valencia. After going 1-0 with a 6.08 ERA in three starts for Toronto, Hendricks pitched in six games (three starts) for the Royals, going 0-2 with a 4.66 ERA in 19.1 innings.
Hendriks has a lifetime 5.92 ERA in 39 career appearances spanning four seasons.
The 25-year-old is from Australia and was signed by the Minnesota Twins as an amateur free agent in 2007.
The Royals lost Game 7 of the World Series on Wednesday night to the San Francisco Giants. It was Kansas City's first World Series appearance since 1985.
Toronto finished the regular season 83-79 and in third place in the AL East.
- Molly Geary