Price was released at the end of last season.
The Millers head out to Vienna on Sunday.
The 21-year-old has arrived on a season-long loan.
The players are back after just 37 days off this summer.
The Guest and Chrimes building has been derelict since 1999.
The defender penned a three-year deal at the Millers on Friday.
Vassell explains what made him join the Millers.