Terry finished his 15 year Hall of Fame career by playing 15 games for the Royals in 1991. Prior to that Terry played 1531 games with Houston from 1977-90.
Mark Teahen played five years with the Royals from 2005-09 and played in 676 games with 59 homeruns and a .269AVG.
Mark was a first round draft pick by the Oakland A’s in 2002 and on June 24, 2004 he was traded as part of a 3-team trade by the Oakland Athletics with Mike Wood to the Kansas City Royals. The Houston Astros sent Octavio Dotel to the Oakland Athletics. The Houston Astros sent John Buck and cash to the Kansas City Royals. The Kansas City Royals sent Carlos Beltran to the Houston Astros.
Matt Stairs played three years the Royals from 2004-06 and played in 330 games with 39 homeruns and a .269AVG.
Overall, Matt played 19 years in the big leagues from 1992-2011 and played in 1895 games.
Aaron Guiel played five years with the Royals from 2002-06 and played in 263 games with 31 homeruns and a .245AVG.
Others include George Kottaras (2013), Jeff Francis (2011), Ryan Braun (2006), Paul Spoljaric (2000) and Andy Stewart (1997).
Canadians who have played Major League Baseball in Kansas City, but not with the Royals: Milt Whitehead (Cowboys-1884), Hall of Famer Bill Phillips (Cowboys-1888), Ozzie Vanbrabant (Athletics-1955), Eric MacKenzie (Athletics-1955), Hall of Famer Reno Bertoia (Athletics-1961), Hall of Famer Ted Bowsfield (Athletics- 1963-64), Vern Handrahan (Athletics-1964, 66), Tom Harrison (Athletics-1965),