One bad series, one good for Packers' QB Aaron Rodgers in debut vs. 49ers

On his first series, Aaron Rodgers and the Green Bay Packers looked like an offense that hadn't played together in the preseason. On the second series, they looked like the kind of offense that could dominate the NFL.

That was the extent of Rodgers' work in Friday's 21-10 preseason win at the San Francisco 49ers, and it might be all the action he gets this preseason. He did not play in the first two preseason games and isn't expected to play in next week's finale.

Rodgers' first drive was marred by penalties, including one that wiped out what would've been a 48-yard catch and run by Davante Adams (who had an up-and-down night) and forced the Packers to punt.

On the second drive, Rodgers got in sync with Randall Cobb, who caught three passes for 30 yards. It was Cobb's 6-yard touchdown on a dump-off pass that accounted for the Packers' only first-half points.

"I thought that both of the series with the mechanics and tempo [were good]," Packers coach Mike McCarthy said in halftime quotes distributed by the team. "We had the penalties on the first series, but yes I feel very good about where Aaron is."

Rodgers finished 6 of 9 for 60 yards and the lone touchdown.

QB depth chart: With Brett Hundley sidelined again because of an ankle injury, rookie Joe Callahan relieved Rodgers. Callahan's best throw might have been a roll-out deep pass for Adams, who dropped it in the end zone. Callahan then barely missed rookie Trevor Davis on a deep ball early in the third quarter. Still, Callahan might have shown enough that the Packers wouldn't have to bring in someone else to back up Rodgers if Hundley isn't ready for the regular-season opener. Callahan completed 16-of-24 passes for 167 yards and one touchdown, including a perfectly placed corner route to Geronimo Allison for a 10-yard gain to convert a fourth-and-9 in the third quarter. That led to Callahan's 18-yard touchdown on a play-action rollout pass to Jared Abbrederis. In the fourth quarter, Callahan avoided a sack and launched a 51-yard bomb to Allison that set up a 19-yard touchdown run by Brandon Burks.

When it was starters vs. starters, the Packers looked ...: Inconsistent. In addition to Rodgers' two series, the defensive starters started strong with a three-and-out but then looked shaky against the run. The 49ers averaged 6.0 yards per run in the first half, when the Packers' starters played extensively.

Who got hurt?: Rookie Jason Spriggs, the No. 2 left tackle, came out in the second half with a club cast on his right hand. He did not have the cast on in the first half. Safety Chris Banjo and outside linebacker Jayrone Elliott, two of the Packers' best special-teams players from last season, both left in the second quarter because of hamstring injuries. John Crockett, who appeared to have a hold on the No. 3 running back job, sustained a shoulder injury in the third quarter.

A surprise player who impressed: Allison has been one of the most impressive receivers all preseason, even if the Packers don't have room for him on their roster. He caught three passes for 78 yards.

One reason to be concerned: The Packers' already thin defensive line was missing two players expected to be major contributors: Kenny Clark (back) and Letroy Guion (knee). Guion's injury is not serious, but there's no word on the severity of Clark's back injury that kept him out of practice last week.

Cook impressive: Tight end Jared Cook was as advertised in his Packers debut. The free-agent signing caught four passes for 54 yards, including a 19-yard slant (with 11 yards after catch) from Rodgers to convert a third-and-2 on the first drive. Cook also caught passes from Callahan to covert a third-and-5 and a fourth-and-4.

Up-and-down Adams: After Adams dropped what would've been a 38-yard touchdown from Callahan, he came back on the same drive to make an extremely difficult 8-yard catch on a slant to convert a fourth-and-5.

Punting competition: Veteran punter Tim Masthay might have been on the ropes heading into the game, but he hit a couple of solid punts -- a 39-yarder with 4.67 seconds of hang time that was fair caught inside the 20 and a 49-yarder (aided by roll) that hung for 4.77 seconds. Challenger Peter Mortell bounced back with perhaps the best punt of the night, a 50-yarder with 4.5 seconds of hang time in the third quarter after two low punts in the first half. This competition might still be too close to call.