Jon Heyman has a story on Nelson Cruz, in which he says Cruz's former agents approached the Rangers this past offseason seeking a 4 year, $56 million contract extension.
The Rangers, unsurprisingly, said no, and the real story here is that Cruz's agents came at Texas with such an aggressive request. Cruz was coming off a disappointing season, his defense has been in decline, and he would have been 37 when that extension ended (assuming that the extension would have kicked in after his current two year deal, which covered 2012-13, expired).
This was apparently pre-Biogenesis, but even considering that, I can't imagine the Rangers would have even considered giving Cruz such an extension.
Heyman also talks about Cruz's suspension, and how the Rangers are open to him returning for the playoffs but haven't guaranteed him a spot (though given that the Rangers are having Jurickson Profar DH against lefthanded starters, one has to think that Cruz on the playoff roster is a lock).