According to David White, who covers the Raiders for the San Francisco Chronicle, Oakland defensive end Derrick Burgess was not on the field when the Raiders’ started their voluntary OTA activities this morning. (White announced the news via his Twitter page — for a good chuckle, you might want to see how he tweeted his way through a sloppy Oakland practice.) Burgess has been the subject of trade rumors — WEEI.com confirmed Monday that the Patriots are interested in acquiring the 30-year-old for either a second- or third-round pick in 2010. (To read more about New England’s interest in Burgess, click here.)