Conversation so far:
can a senior in high school play junior varsity
No, it is a general policy that seniors are not allowed to play Junior Varsity.
Can a junior in high school play junior varsity
Most junior varsity teams consist of players who are in their freshman and sophomore years in school, though occasionally upperclassmen may play on JV teams.

Question: but can a sophomore play in the upper class team
Self-contained rewrite: But can a sophomore play in Varsity teams