Butera, 31, hit .190 (4 for 21) in 10 games with the Angels this season. He batted .188 for the Los Angeles Dodgers last year following four years with Minnesota.
Jackson, acquired in November from the Dodgers, has an .083 average in 20 big league games with St. Louis in 2012-13.
To make room for Butera on the 40-man roster, Kansas City transferred left-hander Tim Collins to the 60-day disabled list. He is recovering from Tommy John surgery in March.
Right-hander Luke Hochevar, who missed last season after elbow surgery, was activated from the disabled list Thursday after nine injury rehabiliation appearances with Triple-A Omaha. The Royals optioned rookie left-hander Brandon Finnegan, who went 1-0 with a 2.70 ERA in four relief appearances, to Double-A Northwest Arkansas.