Raiders 2013 First Round pick CB D.J. Hayden underwent a procedure recently to remove some scar tissue from his abdomen. Apparently, the scar tissue was quite painful for Hayden in his first week of OTAs, and most of his fellow Raiders' defensive backs took notice. Hayden will likely be out the full six weeks (projected recovery time) after his surgery. This would leave him available for training camp, provided he's 100% and feeling ready.
Thanks to RaiderCentral on YouTube.