If the only thing he can do now is DH at his present rate of production then shelve him for the remainder of the season do whatever "medical intervention" and come back next season and assess what you have/dont have.
My 1st choice would be get rid of both Gallo and Kepler. If only one goes make it Kepler and his sub .700 OPS since 2021.
This isnt a down year for Kepler. This is what Kepler is.
I'd be ecstatic if the current Twins MLB level hitting coaches stay far away from the young Twins hitters. Then again I've been calling for the Twins hitting coaches to be replaced for months.