12:31pm: The Raiders announced (on Twitter) that the deal is official.
12:09pm: The Raiders have reached agreement with safety Nate Allen, Vic Tafur of the San Francisco Chronicle tweets. The deal was completed in essence last night but the two sides tied up some loose ends this morning, according to Scott Bair of CSNBayArea.com (via Twitter).
Allen, 27, started 15 games for the Eagles last season at safety, racking up 62 tackles, four interceptions, three fumble recoveries, five pass deflections, and a sack. Allen had a pretty solid year in 2014, finishing out with a 3.9 overall grade according to Pro Football Focus (subscription required), good for 28th out of 87 qualified safeties.
Safety has been a need for the Raiders since the release of Tyvon Branch back in February. Branch, 28, started 62 out of a possible 64 games in his first four years but he missed all but five games over the past two seasons.