Watch: 49ers linebacker Dre Greenlaw suffers Achilles injury running onto field

Officials initially ruled it as "a lower left leg injury," with CBS Sports' Evan Washburn reporting Greenlaw was "unable to put weight" on his leg. He was taken to the locker room by cart for further evaluation.

ESPN's Adam Schefter reported Greenlaw suffered an Achilles injury. Later, the team ruled him out for the remainder of the game.

Greenlaw was a key player in San Francisco's divisional-round win over the Packers. He had two interceptions in the second half, the first leading to a field goal and the last sealing the 24-21 victory.

Greenlaw was second on the team in tackles (120) despite only playing in 15 games. He missed Week 6 against the Browns with a hamstring injury and also didn't suit up in Week 18 after the 49ers clinched the NFC's No. 1 seed.