San Francisco 49ers

Halftime: 49ers’ starting offense struggles; Gabbert strikes back

At least no one is talking about the field anymore.

Instead, the hot 49ers topic was the ice-cold start from San Francisco’s first-team offense and a resurgence from backup quarterback Blaine Gabbert. He tossed the team's first touchdown of the preseason, a six yarder to tight end Vance McDonald that gave the 49ers a 10-7 lead at the break.

The previous two preseason outings, in which the 49ers were outscored 57-3, were explained away by saying the team hardly played any of its starters.

That wasn't the case today as San Francisco was at near full strength but still struggled, particularly the offense in the first quarter. Starting quarterback Colin Kaepernick was rattled and was hit four times, including on a scramble during which he was hit hard from behind and fumbled and on a sack from behind that also resulted in a fumble.

The lapses came not from the right side of the line where Joe Looney and Jonathan Martin are filling in for missing starters Alex Boone and Anthony Davis, but from the left side. Guard Mike Iupati, who is hoping for a big pay day in the upcoming free-agent market, was the main culprit, allowing his man to slip free on several occasions.

The 49ers' offense finally began to click in the second quarter when Kaepernick hit five straight passes before the drive bogged down at the San Diego 21-yard line. Phil Dawson was good from 39 yards, giving the 49ers their first points at Levi's Stadium.

The 49ers tinkered with their offensive line throughout the first half, playing Adam Snyder at both right and left guard on different drives and using rookie Marcus Martin at center late in the second quarter. Kaepernick left the game 6-12 for 59 yards.

Gabbert, who entered with a lousy 17.9 passer rating, was 5-7 on the team's final drive of the half, including a nice toss to rookie Bruce Ellington on a crossing pattern that picked up 19 yards. Gabbert's passer rating is 136.9.

For the first time this season, a bevy of defensive starters played in the game. That included the entire defensive line – Justin Smith, Ian Williams and Ray McDonald – as well as linebacker Patrick Willis and cornerback Tramaine Brock.

That unit held up well when San Diego took over deep in San Francisco territory after Kaepernick's second fumble. Wilhoite and Willis teamed to stop the Chargers on fourth and 1 from the 5-yard line

Later in the first quarter, however, the Chargers put together a 10-play, 71-yard that ended in a touchdown.

For the second straight week, the opposing tight end caught an intermediate-length pass in the end zone while being covered by safety Craig Dahl, who seemed to be looking for inside help from a linebacker, in today's case, Patrick Willis. Dahl is playing in place of Antoine Bethea, who suffered a concussion last week.

Chargers quarterback Philip Rivers left the game 9-10 for 85 yards and one touchdown.