The 19 year-old nippy forward is yet to play for Southampton's first team from the start, but has figured as a substitute and spent eight years in their academy, top scoring for the Under 18 side last year.
He has also spent time on loan at Preston North End.
The red headed Hoskins is expected to sign for the rest of the season at Don Valley on Thursday morning.
We wish him the best of luck in a Millers shirt.