The thing I do like about Baker is he effort was consistent and the was one of the few guys who was physical out there, understanding that TG wants less hitting and more skating.
I think Zimmer being a Senior will play against him as younger players and potentially players brought in by this staff (more upside potential) will get playing time before him. Baker is an Assistant Captain so I think he is a leader and his hard-nosed approach will be kept in the lineup.
Just my $.02 on the rationale I was thinking about.