SANTA CLARA – Linebacker Kwon Alexander will be back on the field Saturday when the 49ers open the playoffs, but he likely won't step into his old every-down role quite yet.

Alexander is just nine weeks removed from surgery to repair a torn pectoral. He returned to practice last week and remains on injured reserve. The 49ers plan to activate him to the 53-man roster to play Saturday against the Minnesota Vikings at Levi’s Stadium in the NFC divisional round.

The 49ers know what to expect from Alexander. But they also do not know exactly what to expect.

“I know Kwon will fly around,” 49ers coach Kyle Shanahan told NBC Sports Bay Area. “He’ll hit. He’ll be energetic. He’ll get everyone going. I think everyone will feel his energy on the field. And we’ll see how it goes.

“We’re not going to throw him out there, just down-in and down-out. But we don’t have a plan, where it’s only going to be ‘this’ amount. He’s looked good in practice, but we’re also not laying people out in practice.”

Kwon Alexander at #49ers practice today, as he is on pace to play Saturday after sustaining torn pec on Oct. 31.

WATCH: pic.twitter.com/UzmZIq58US — Matt Maiocco (@MaioccoNBCS) January 8, 2020

Rookie Dre Greenlaw played the weakside linebacker position during the second half of the season in Alexander’s absence. Greenlaw made the big defensive play of the season in Week 17 when he stopped Seattle Seahawks tight end Jacob Hollister just inches short of the goal line on a late-game fourth-down play. The tackle preserved the 49ers' 26-21 win and wrapped up the NFC West and home-field advantage in the playoffs.

The 49ers’ three linebacker positions are similar, so the team will have some decisions to make on how they want to use Greenlaw and Alexander alongside middle linebacker Fred Warner. Shanahan said a lot of the team’s in-game decision-making will be in reaction to Alexander’s effectiveness.

“You got to wait to see how the tackling goes and how he feels,” Shanahan said. “(He is) someone we’ll be communicating with throughout the game.”

[RELATED: Kittle feels 'great' despite having to wear extra padding]

Alexander and strong safety Jaquiski Tartt are expected back in the starting lineup Saturday. Tartt missed the final four games of the regular season with fractured ribs. The 49ers also are hoping defensive end Dee Ford is fully back from a hamstring injury that limited him to just four snaps in the final six games. Ford’s status remains uncertain, as he appeared to show some signs of fatigue Wednesday after a heavier workload in practice Tuesday.

“All three of them are a little bit different,” Shanahan said. “Some guys have been out for a while. You never want to put them back in there too much. It’s a little unfair to them even if they are ready to go because you got to go through some mistakes when you’re just a little bit rusty, and that can be tough on a guy, especially at this time.”