Update (1:50 AM ET): The deal is official.
Kela, 25, has been solid out of the bullpen for the Rangers, putting up a 3.44 ERA with 44 strikeouts and 14 walks in 36 2/3 innings. The right-hander is owed the remainder of his $1.2 million salary and is arbitration eligible for three more years.
The Rangers and Pirates are headed in different directions. At 46-62, the Rangers have already begun to sell off, having traded Cole Hamels to the Cubs. The 55-52 Pirates find themselves in the thick of things in the NL Wild Card race and could be contenders in the NL Central as well.