Bradford have allowed defender Guy Branston to join Rotherham on a three-month emergency loan deal.
Branston previously played for the Millers between 1999 and 2004 and was part of the side that won back-to-back promotions to the Championship in the early 2000s.
The 32-year-old centre back told Rotherham's official website: "I got a phonecall (on Thursday night) from my gaffer (Phil Parkinson).
"I was very surprised but when I asked who the club was and he explained I thought it was an opportunity to come and play football.
"That is what I'm about, I don't believe in sitting on benches so I decided to take the opportunity to sign for Rotherham and I have got a big grin on my face, I am very pleased."
The switch is subject to Football League clearance.