Heyward-Bey did not talk to reporters following the game, and Boss said Monday he was surprised at his lack of playing time.
"I've got a lot of confidence in myself and feel like I can help this team but, you know, that's something I can't do when I'm not playing," Boss said. "But I think that things will work (themselves) out and I feel confident that I'll get back out there and continue to do what I've done in the past, and that's make plays and be a solid tight end."
Jackson said he talked to the players before the game and that everyone was aware of their role going into Sunday.
"Do I think some players walked out of here yesterday feeling like they could have made more of a difference in the game? Probably so," Jackson said. "When you lose, everybody has a reason why you lost. But when you look at it, that's not why we lost. We lost because of penalties. We lost because we didn't do a good enough job of taking care of the ball, and we didn't stop the run."
The Oakland Raiders' 84 penalties are an NFL-high and 14 more than any other team in the league has.
"Some of 'em are just bonehead mistakes that we need to clean up," defensive tackle Richard Seymour said. "We need to eliminate bad football, and that's part of the bad football side of it. You won't win a lot of games (and be) where you want to be at the end of the year if we continue to do this."
The Associated Press contributed to this report.