Nick Bosa, who missed time last week with a concussion, will play for the 49ers.

Two of the 49ers’ best defenders, after leaving last week’s game against Dallas with injuries, will be available on Saturday night. The team announced Friday that star defensive end Nick Bosa, who missed the second half with a concussion, has been cleared to play again. He will join linebacker Fred Warner, who had sprained an ankle, in San Francisco’s stellar front seven.

Coach Kyle Shanahan also said Thursday that quarterback Jimmy Garoppolo, hampered by a torn ligament in his right thumb and a sprained right shoulder, will be ready.

“And he’s thrown the ball great,” Shanahan said. “He’s looked as good as he did the week before.”

The Packers, benefiting from the first-round bye awarded to the N.F.C.’s top seed, also regained a slew of reinforcements. They activated from injured reserve receiver Randall Cobb, out since late November after undergoing core muscle surgery; linebacker Za’Darius Smith, who hasn’t played since Week 1; and linebacker Whitney Mercilus, who tore his biceps Nov. 14 against Seattle.

The offensive line will regain right tackle Billy Turner, who has missed the last month with a knee injury, and center Josh Myers, who played 32 snaps in the season finale in his first action since injuring his knee in Week 6. Also Cornerback Jaire Alexander (out since Week 4 with a shoulder injury), though listed as questionable before the game, will likely play.

Left tackle David Bakhtiari, who played 27 snaps in Week 18, his first game since tearing a knee ligament last season, was declared out just before the game, as was receiver Marquez Valdes-Scantling (back), a top downfield threat who had been doubtful.