MONDAY: The Rays have officially activated Crain and designated Martin for assignment, tweets Mooney.
SUNDAY: The Rays will designate pitcher J.D. Martin for assignment on Monday, Roger Mooney of the Tampa Tribune reports (on Twitter). The move will clear space for fellow pitcher Jesse Crain, who is on the 60-day DL.
Martin was outstanding in 160 1/3 innings for Triple-A Durham this year, posting a 2.75 ERA with 6.5 K/9 and 1.5 BB/9 and winning International League Most Valuable Pitcher honors. The 30-year-old has not pitched in the Majors since 2010, when he started nine games for the Nationals. The Rays promoted him before Sunday's game in order to have him available in the bullpen.
As is the case with all DFAs, Martin's status can be monitored using MLBTR's DFA Tracker.
Steve Adams contributed to this post.