Why is Vernon Davis invisible in red zone?

After 10 games, are you still trying to figure out why Pro Bowl tight end Vernon Davis has become a virtually invisible man in the San Francisco 49ers' red zone offense?

If so, you're not alone.

"I don't know why, I don't know why, either," Davis said this week. "For me, I've been here for going on nine years now, and all I can do is just take care of my assignments and do my job and play as hard as I possibly can and do whatever it takes to help this team win. And that's what I'm here for.

"As far as not getting those touchdowns and those yards, I'll leave that up to the coaches."

Consider: Last year, Davis was targeted 17 times in the red zone, coming away with 11 catches and eight touchdowns.

This year, Davis has been targeted once. Yes, once. That was in the season opener at the Dallas Cowboys. The result? A 2-yard touchdown catch in the first quarter that gave the 49ers a 21-3 lead en route to a 28-17 victory at Jerry World.

"I just feel like he's ready to break out, I really do," 49ers coach Jim Harbaugh said Friday of Davis. "You use the old olive jar analogy.

"The olives are packed in there real tight, and you open up the lid and you can't get any to come out. You can even dump it upside down and it doesn't come out. But if you get that one to come out, then they just want to all come out and plop out."

Are you picking up what Harbaugh's putting down as the Niners prepare for Sunday's game against the Washington Redskins at Levi's Stadium?

"So, I think that's the case, and I think it's going to happen soon," he added. "Hopefully this weekend. Get that one big one and then they start coming out."

Granted, Davis has dealt with ankle, knee and back issues, and he has missed two games, his most since missing two in 2007. And many critics charge that it looks as though Davis is not going all out for passes not thrown directly at him.

But Davis said he has been healthy since the bye week, four weeks ago. And he has not talked to the coaches about his diminished role and productivity in the red zone this season.

"They're aware," Davis said. "So I let them continue to do their job, and I'll do mine.

"Everything always works itself out. Especially if you're working hard and you're doing the right things, it will come. It will come. It's just a matter of time. I know that I have to be optimistic. I keep my faith and just keep working hard."