Lumsden was obtained with right-hander Dan Cortes from the Chicago White Sox on July 24, 2006, in a trade for right-hander Mike MacDougal.
At the time, Lumsden was 9-4 with a 2.69 ERA in 20 games for Double-A Birmingham. He finished the season with a 2-1 mark and a 3.06 ERA in seven games for the Royals' Double-A Wichita club.
After a 9-6, 5.88 ERA season in 2007 for Triple-A Omaha, he was with the Royals in Spring Training and was again assigned to Omaha. However, he struggled, with a 3-13 record and a 7.21 ERA this season in 28 games (18 starts).
"He's got good stuff: an above-average fastball, a good curveball and a changeup," said Royals assistant general manager J.J. Picollo. "He just hasn't been able to put it together."
To clear space on the 40-man roster, the Royals designated Lumsden for assignment last Thursday, and the Astros showed interest.
"Tyler's numbers weren't good this year, but our guys like his arm," said Astros general manager Ed Wade. "He's a big, strong lefty, and he's only 25 years old. He has remaining options, so we'll get him into Kissimmee, [Fla.,] evaluate him and give him a chance to compete. At the very least, Tyler provides us with some more young depth."
Lumsden has not pitched in the Majors. In 95 Minor League games, he's 26-25 with a 4.89 ERA. He was selected by the White Sox as a sandwich pick between the first and second rounds of the 2004 First-Year Player Draft.
Dick Kaegel is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.