Davey told the Tykes' official website: "Unfortunately Anderson has ruptured his cruciate ligament and will be out for a minimum of six months. Our thoughts are with him at the moment but the entire club is distraught.
"He's not had his operation yet and is with his family. We're thinking of him and I'm sure that everybody will wish him a speedy recovery.
"We had a clinical assessment done and then followed that up at the back end of the week with an MRI scan which has shown that Anderson has ruptured his cruciate.
"He's distraught, we as a club are distraught and it's a massive blow to us after chasing him all season. We'll support him as best we can through a long rehab programme."