Fri, 03 Aug 2012 17:31:00 – Ravenhill limped off during the Bantams' 4-0 friendly defeat of Guiseley on Wednesday and a scan has revealed ligament damage.
"Ricky looks like he'll be out for around three months. As we thought initially, it's damage to his medial ligament," Parkinson told the club's official website.
"It's a strange one because he's not in a great deal of pain but there's some looseness in the joint which the specialist is worried about. He's now going to have to go in a protective knee brace for around four weeks initially to help the healing process.
"It's something we just have to take on the chin and move on from. It's a blow for him and it's a big blow for us because Ricky is a key player.
"He's a key character around the dressing room and there's no doubt that we'll miss him, but unfortunately we have to move on and get used to being without him for the next few months."