Both pitchers have struggled this season and the two teams agreed on a trade, hoping a change of scenery would be best for both.
Sanchez was 1-6 with a 7.76 ERA in 12 starts for the Royals.
The Royals designated him for assignment earlier this week.
Sanchez was acquired in a now infamous trade with the San Francisco Giants.
The Royals sent Melky Cabrera to the Giants for Sanchez in that trade.
Guthrie came to the Rockies an off-season trade with the Baltimore Orioles. Jason Hamel was sent to the Orioles in exchange for Guthrie.
Guthrie was 3-9 with the Rockies and pitch to a ERA of 6.35. he was sent to the bullpen after struggling in his first nine decisions.
Both pitchers have had success in the past, and perhaps a change of scenery will affect a change in their pitching performances.