Free-agent catcher Jason Castro is talking with the Twins, as well as the Rays and Braves. As written here last week, Castro will get at least a three-year deal, with the possibility of a fourth year.
Once Castro signs, the most prominent catcher available will be Matt Wieters, the longtime Orioles catcher. Baltimore did not extend a qualifying offer to Wieters this year following a season in which his offensive production declined, as well as his defense, according to some evaluators. Club executives have increasingly focused on pitch-framing as a valued skill -- this is why Castro is getting three-year offers -- and Wieters had some of the game's worst pitch-framing stats in 2016.
The Twins and Rays want Castro, but it's not clear whether either team has any interest in Wieters, in part due to the poor pitch-framing metrics.