NAPA — The Raiders began their regular-season routine Tuesday in preparation for what amounts to their most important dress rehearsal of the preseason.

Oakland hosts the Detroit Lions Saturday at O.co Coliseum, with the third game of the preseason typically being the closest thing approximating a regular-season routine.

Unlike Oakland’s previous two games, a 3-0 loss to the Dallas Cowboys and a 31-27 defeat against Arizona, the Raiders will actually game-plan for an opponent for the first time and will play most starters into the third quarter.

In a departure from previous years, coach Dennis Allen took the extra step of instituting in-season media access, meaning reporters were restricted to the first half-hour of practice. During that time, the club goes through warm-ups and some drills, with the media being excused once they go to team sessions.

Every other season since 1996, practices were open all the way through training camp and practices closed once the team returned to its home facility in Alameda. The Raiders practice Wednesday and Thursday in Napa before breaking camp.

Players who were not present or did not appear to be practicing as the team sessions began included wide receivers Jacoby Ford (foot) and Denarius Moore (hamstring), running back Rashawn Jackson (hip), linebacker Aaron Curry (knees), center Stefen Wisniewski (calf), tackle Ed Wang (shoulder), tackle Zach Hurd (head), defensive tackle Richard Seymour (veteran’s day off) and defensive tackle Jamie Cumbie (foot).

Players who were back at practice included safety Michael Huff (paternity leave), quarterback Matt Leinart (lacerated right index finger) and wide receiver Darrius Heyward-Bey (shoulder).

The Raiders must cut the roster to 65 players by 1 p.m. on Aug. 7, with the 53-man roster finalized on Aug. 31 by 6 p.m.