To make room for Griffin on both the 25-man and 40-man rosters, outfielder Justin Ruggiano has been designated for assignment.
Signed to a minor league contract with a spring training invitation on January 12, 2016, Griffin was assigned to Round Rock on April 2 but did not appear with the Express. He was 1-2, 6.00 in 6 games/4 starts with Texas this spring.
The righthander saw no major league action the previous two seasons after undergoing ligament replacement surgery on his right elbow on April 30, 2014. He missed all of 2014 and appeared in four minor league games on rehab assignment in the Oakland organization in 2015 before being released by the A's last November.
Griffin was 14-10, 3.83 in 32 starts with Oakland in 2013. His last appearance in the majors was a loss on September 24, 2013 against the Angels in Anaheim. His last big league victory came on Sept. 12, 2013 at Minnesota. Griffin is 21-11, 3.60 in 47 starts with Oakland in 2012-13.
Ruggiano has appeared in one game this season, going 1-for-4 with an RBI in a start in left on Wednesday vs. Seattle. Texas has ten days to trade, release, or outright Ruggiano to the minor leagues.
With today's moves, the Rangers' major league roster remains at 40 players.