San Francisco 49ers linebacker NaVorro Bowman, one of the few players left from the Jim Harbaugh era, left Sunday’s game against the Dallas Cowboys due to injury.

The injury itself looks to be to Bowman’s Achilles. He was carted to the locker room after suffering the non-contact injury.

https://twitter.com/FanSportsClips/status/782708586182873088

We hate to speculate on the seriousness of injuries, but there’s a couple things to look at here.

First off, Bowman went down in a heap, a clear sign that it might be a ruptured Achilles.

Secondly, San Francisco ruled him out for the game immediately after he was taken to the locker room.

NaVorro Bowman is out with a lower leg injury. #DALvsSF — San Francisco 49ers (@49ers) October 2, 2016

Indicators are not good here for Bowman and his 49ers.

One of the top defensive players in the NFL when healthy, Bowman missed the entire 2014 season after tearing up his knee in the 2013 NFC Championship game against the Seattle Seahawks.

Bowman rebounded well upon his return, leading the NFL with 154 tackles en route to earning All Pro honors last season.

If this is indeed a serious injury, the impact it will have on the 49ers’ defense is huge. He’s not only seen as a team leader, he’s the most-talented player on what has been a struggling defense in the first three weeks.