SANTA CLARA -- Alex Boone, the 49ers' burly right guard, wouldn't have fined the Green Bay Packers' Clay Matthews $15,000 as the league did for a late hit on Colin Kaepernick.

"I probably would just punch him in the face. I don't want his money," Boone said Friday after the league announced fines from the 49ers' 34-28 season-opening victory.

Two 49ers, linebacker Ahmad Brooks and wide receiver Anquan Boldin, got fined more combined than Matthews for their infractions Sunday. Brooks was docked $12,750 for a roughing-the-passer penalty, and Boldin was fined $7,875 for a late hit on Jarrett Bush.

It was Matthews' out-of-bounds tackle of Kaepernick, however, that sparked a sideline scrum and critical comments from 49ers coach Jim Harbaugh.

Harbaugh's reaction Friday to the fines: "I have zero reaction to the fines. At the direction of the league, I have nothing to say about that publicly."

No fines came from Matthews' post-tackle melee during which, television replays indicated, Matthews struck 49ers left tackle Joe Staley twice in the head. Those swings by Matthews were described as one punch and one slap by Harbaugh, who on Monday mocked the slap and suggested that Matthews "come with some knuckles" next time for his "tough guy" image.

Boone apparently took that advice to heart with his proposed sanctions against Matthews. Matthews' verbal counterpunch Thursday: "I'm an awesome player. I'm not a dirty player."

Brooks' penalty occurred 1:24 before halftime and it ignited a tying touchdown drive by the Packers. Boldin wasn't penalized during the game for his third-quarter hit on Bush, which apparently came after Kaepernick ran out of bounds on a 15-yard scramble.

  • Of Aldon Smith's 35 career sacks since 2011, only two have come against the Seattle Seahawks, who have shut out the 49ers sack artist in two of four matchups.

    One major obstacle between Smith and Seahawks quarterback Russell Wilson on Sunday night will be left tackle Russell Okung.

    "He's probably the best left tackle -- one of the best left tackles that we've gone against since we've been here," said Vic Fangio, the 49ers' third-year defensive coordinator. "He's an excellent tackle. He does give us some problems."

    Okung was drafted sixth overall in 2010 and made his first Pro Bowl last season.

    Smith sacked Wilson on the Seahawks' final drive last October, when the 49ers pulled out a 13-6 victory at Candlestick Park. As a rookie, Smith's 14th and final regular-season sack came at Seattle.

  • Harbaugh "feels good" about the offense's preparation for a Seattle crowd that could make play calls challenging.

    Boone said Kaepernick's calls aren't shortened and that the huddle is kept tight to block sound while Kaepernick gets lower to the ground in relaying assignments.

    "This game, you've got to focus or you'll be lost in space," Boone said.

  • The only player on the 49ers' injury report is running back/returner LaMichael James (knee). He is questionable and hasn't practiced since spraining the knee Aug. 29.

  • Seahawks cornerback Brandon Browner (hamstring) is doubtful and Walter Thurmond probably will start in his place.

  • Defensive end Cliff Avril, a nemesis in recent years for 49ers tackle Anthony Davis, is "probable" for his Seahawks debut after battling a hamstring strain. Avril played his first five seasons with the Detroit Lions.

    Seahawks defensive end Cris Clemons (knee) is questionable.

    For more on the 49ers, see Cam Inman's Hot Read blog at blogs.mercurynews.com/49ers. Follow him on Twitter at twitter.com/CamInman.