1:41pm: Grant has tweeted a correction, saying Madrigal has not been designated but instead transferred to the 60-day DL. According to MLB.com's T.R. Sullivan, Major League Baseball told the Rangers they were not comfortable with Madrigal being designated while still on the 15-day DL.
1:21pm: The Rangers designated righty Warner Madrigal for assignment to make room for Matt Treanor, tweets Evan Grant of the Dallas Morning News. The potential loss of Madrigal is linked to catcher Jarrod Saltalamacchia, who was slow to notify the team about a back injury.
Madrigal, 26, struggled in 12.6 big league innings last year. He was solid in Triple A, posting a 2.57 ERA, 8.8 K/9, and 2.0 BB/9 in 49 innings. Madrigal began his career as an outfielder in the Angels organization. According to Baseball America, the Halos "inadvertently failed to place him on the 40-man roster before the end of the  World Series," allowing the Rangers to sign him as a minor league free agent. Madrigal threw in the mid-90s back then, but averaged 91.4 mph in the Majors last year. Madrigal was recently placed on the DL with forearm tightness.