Millwall have completed the signing of Danny Shittu on a one-year contract.
The 31-year-old had been training with the Lions following his release from Queens Park Rangers at the end of last season.
Making way for Shittu at the New Den is Scott Barron, who has agreed to join Brentford, subject to a medical.
Shittu played 10 times for Millwall during a brief stint with the London club in 2010.