SANTA CLARA, Calif. — In the past, Vernon Davis might have been worried by this point in the preseason about his opportunities once the season opener rolled around. But the San Francisco 49ers tight end was smiling today.

"My role is going to be major in this offense, major," Davis said after the 49ers' morning walkthrough practice.

So far, Davis' numbers have been anything but major. Davis has just four catches for 72 yards and no scores through the first three exhibition games. He's been more of an afterthought than a featured weapon in new offensive coordinator Mike Martz's scheme.

But Davis says Martz has yet to unveil the total package being prepared for when the real games begin.

"There's a lot of stuff we run in practice that we don't get a chance to run in preseason just because we don't want to reveal too much," Davis said.

Instead of consistently lining up in a three-point stance directly next to an offensive tackle, as he did last season, Davis said he'll line up everywhere imaginable in order to get mismatches and get open.

Davis offered a glimpse Thursday night against the Chicago Bears of what he hopes to do often this season. On first-and-10 from the 49ers' 23 early in the second quarter, Davis raced deep downfield and caught a 40-yard pass from quarterback J.T. O'Sullivan.

The tight end has never been much of a receiving factor in Martz's past offenses in St. Louis and Detroit. But Martz has not had a tight end like Davis, who combines size and strength with a wide receiver's speed.

"He's had some good tight ends in the past, but they've been kind of blocker or receiver, one or the other," Niners coach Mike Nolan said. "But with Vernon, he's pretty versatile."

Davis said he and O'Sullivan, the team's new starting quarterback, are developing good chemistry as the Sept. 7 season opener approaches.

"He knows my speed. He knows where I'm going to be. He knows how to throw it and when to put it there," Davis said.

Nolan named O'Sullivan his starter on Friday, ending a battle with Alex Smith and, to a lesser degree, Shaun Hill. Asked whether he thought Nolan made the right choice, Davis said all three quarterbacks played well.

Last season, Davis caught 52 passes — ninth among NFL tight ends — for 509 yards and four touchdowns. This season, he said he expects bigger numbers and maybe a trip to the Pro Bowl.

"That's possible," Davis said. "But first, get some wins."

NOTES: OG David Baas (pectoral) came off the physically unable to perform list and practiced for the first time this preseason. Nolan hopes he can play at least a quarter Friday night against San Diego. WR Ashley Lelie (calf), a former Radford High and University of Hawaii athlete, and RB Michael Robinson (knee) practiced.