FILE - In this Oct. 31, 2019, file photo, San Francisco 49ers linebacker Kwon Alexander (56) looks on during the first half of an NFL football game against the Arizona Cardinals, in Glendale, Ariz. Alexander has returned to practice for the San Francisco 49ers on Thursday, Jan. 2, 2020, for the first time since tearing his pectoral muscle midway through the season. The Niners opened up the three-week practice window for Alexander to be activated from injured reserve in the playoffs. (AP Photo/Rick Scuteri, File)
FILE - In this Oct. 31, 2019, file photo, San Francisco 49ers linebacker Kwon Alexander (56) looks on during the first half of an NFL football game against the Arizona Cardinals, in Glendale, Ariz. Alexander has returned to practice for the San Francisco 49ers on Thursday, Jan. 2, 2020, for the first time since tearing his pectoral muscle midway through the season. The Niners opened up the three-week practice window for Alexander to be activated from injured reserve in the playoffs. (AP Photo/Rick Scuteri, File)

SANTA CLARA, Calif. (AP) — The San Francisco 49ers activated linebacker Kwon Alexander from injured reserve Friday to make him eligible for the team's playoff opener against the Minnesota Vikings.

Alexander initially got injured on Oct. 31 when he tore his pectoral muscle in a win at Arizona. He was placed on injured reserve and wasn't expected back this soon.

Alexander managed to heal more quickly than anticipated and returned to practice last week and was cleared by doctors to play Saturday against the Vikings.

Alexander is a key part of San Francisco's defense with his speed in coverage and the energy he brings to the unit. He had 34 tackles, four passes defensed, one interception, one forced fumble and a half-sack in eight games this season.

The 49ers placed defensive lineman Kentavius Street on injured reserve with a knee injury to make room on the 53-man roster.

___

More AP NFL: https://apnews.com/NFL and https://twitter.com/AP_NFL