DENVER (AP) -- Peyton Manning looks like he's ready for the regular season, although he'll never admit it.

"We've still got another week. I think we can use this next week," Manning said after throwing his first two touchdown passes for the Denver Broncos in a 29-24 loss to the San Francisco 49ers on Sunday.

The Broncos (1-2) wrap up the preseason with a trip to Arizona on Thursday night, and it's unlikely that Manning will make even a cameo appearance in that game.

"I'm not sure what the situation will be playing time-wise. I'd like to use this week also to get an extra start on our opener against Pittsburgh. That's what I've done in the past," Manning said. "They're plenty to get ready for so, we can use that time. I think you've got to use every single day of practice, every single meeting in order to get more and more prepared. I'll take all the time we can get."

The Broncos' preseason finale against the Cardinals, however, will be more about determining Manning's primary backup and determining the final roster spots.

Caleb Hanie, rookie Brock Osweiler and Adam Weber have all done very little to distinguish themselves as the man who should back up The Man.

None shined after Manning exchanged his helmet for a visor after giving the Broncos a quick 17-0 lead.

Hanie threw an interception and a touchdown pass, Osweiler was 4 of 9 for 27 yards and Weber 4 of 8 for 38 yards.

The backups for the 49ers (2-1) were much better, erasing a 24-10 halftime deficit on the strength of Anthony Dixon's 26-yard TD run and four of David Akers' five field goals.

Manning was close to perfect in his final regular-season tuneup. In less than a quarter of work, he completed 10 of 12 passes for 122 yards, including TD tosses of 10 and 5 yards to Eric Decker, and the only two misses were a dropped pass by Joel Dreessen and an errant throw to Brandon Stokley, who was held on the play but didn't draw the flag.

After managing one TD to go with four turnovers in his first seven possessions this preseason, Manning drove the Broncos to scores on all three of his series, then put on his visor with 46 seconds left in the first quarter.

"I think it was nice just to start fast and finish off some drives and put some points on the board and play some good football," Stokley said. "I think that was more important than him throwing the first touchdown pass."

The Broncos mixed up their looks, throwing in some no-huddle with four-wide receiver sets, using fullback Chris Gronkowski at the point of attack and sending tailback Lance Ball out wide to run routes like a receiver.

"No matter what grouping we were in we showed we could move the ball," Manning said.

Alex Smith threw a 49-yard TD pass for the Niners (No. 4), who outscored the Broncos' backups 19-0 in the second half but lost wide receiver Ted Ginn Jr. to an ankle injury early in the second half.

For the second straight week, the Broncos' backups were awful. They've now been outscored 40-0 after halftime in the last two games, both at home.

Denver's first drive stalled when the replacement officials failed to whistle cornerback Carlos Rogers for a blatant hold on a third-down pass to Stokley, and the Broncos settled for Matt Prater's 53-yard field goal.

Manning was money after that.

He completed all six of his passes for 83 yards on a long drive that ended with his first touchdown throw in orange and blue, a 10-yard strike to Decker, who beat Rogers across the middle. The highlight of the drive was a 38-yard pass to Ball, who beat linebacker Larry Grant.

Ball bruised his ribs on the play and didn't return. He said afterward he was fine.

So was Manning, who was blasted by linebacker Parys Haralson in the chest right as he released his longest pass of the preseason. After Ball came down with it, Manning bounced right up, raced downfield, lined up in the no-huddle and hit running back Willis McGahee for 14 yards to the San Francisco 12.

It was the second time Manning, who missed all of last season with a neck injury that required four operations, had been hit hard in the preseason, and both times shook off the cobwebs and responded with a big pass for the first down.

Linebacker Wesley Woodyard recovered a fumbled snap for the Broncos at the San Francisco 24, and four plays later, Manning found Decker wide open by the back left pylon for his second touchdown and a 17-0 lead.

The Broncos' onside kick backfired when Matthew Willis touched the ball about a yard early.

"I was surprised," Niners coach Jim Harbaugh said. "But I'm glad they did it. It's good for us because you always have to be aware of it."

On the next snap, Smith saw linebacker Von Miller on tight end Vernon Davis and hit Davis all alone along the left sideline for a 49-yard score.

Smith finished 5 of 7 for 69 yards.

"It was a little hard to get in a rhythm," Smith said, who was sacked just once. "I thought the young guys did a great job in the second half. We have some stuff to clean up obviously."