Baker is fifth in the rotation but will not lose his spot because he is cheap ($400,000) and under the Twins control. If anyone goes it will be Lohse, who will wind up with $4,000,000 or so in arbitration and is a free agent next season. If the Twins need to make room for Liriano, it won't be Baker that gets moved.
Baker is a solid no. 3 or 4 major league starter right now, but he is really polished and doesn't have much more of a ceiling.