Tomko has pitched only 17 2-3 innings in the majors since 2009, making eight relief appearances in 2011 with Texas. He was 4-8 with a 4.98 ERA in 19 starts last year with York in the independent Atlantic League.
Tomko is 100-103 with a 4.65 ERA over 14 major league seasons with Cincinnati (1997-99), Seattle (2000-01), San Diego (2002, 2007, 2008), St. Louis (2003), San Francisco (2004-05), the Los Angeles Dodgers (2006-07), Kansas City (2008), the New York Yankees (2009), Oakland (2009) and Texas (2011).
He was 2-7 with a 6.97 ERA in 10 starts and six relief appearances for the 2008 Royals.
Tomko's deal was announced Friday, when Kansas City also said it had agreed to a minor league contract with right-hander Ramon Troncoso. The 31-year-old was 1-4 with a 4.50 ERA in 29 games last year with the Chicago White Sox. He played for the Los Angeles Dodgers from 2008-11.