Clutch / throwout repair

97 Ranger, 90,000 miles
Trans fluid replaced every couple of years, most recently a few months ago. Always use Mobil1 atf.
This truck is getting progressively harder to shift. Getting into first gear is a real challenge, no grinding, but very hard to engage. 2nd is much easier, but still somewhat difficult. 3, 4, 5 are all just slightly hard to shift into. Very recently developed, reverse can not be engaged (without grinding) unless you shut off the engine first. All gears engage smooth as butter when the engine is off.

I am assuming that this all points to a clutch replacement, correct? If it is the clutch, what should I do about the TOB / slave cylinder. Of course I would replace the TOB. What about the slave cyl? Should it necessarily be replaced too?