Barnsley have signed defender Lewin Nyatanga on a two-year deal.
The 24-year-old centre-half, who had three loan spells with the Reds six years ago, was released by Bristol City earlier this summer and will stay at Oakwell until 2015.
The Wales international said he was sold by manager David Flitcroft's revolution at the South Yorkshire club.
"I've got really fond memories of my time here," he told the club's official website.
"I've spoken with the manager and he's so passionate about what they're trying to do here.
"I've bought into that and I'm coming here with a lot of motivation to help push this club up."