Lions linebacker Derrick Barnes reportedly, unsurprisingly, headed for IR

Linebacker Derrick Barnes, who has become a key piece of a defense that has become very good, was on the lengthy list of injuries for the Detroit Lions coming out of the Week 3 win over the Arizona Cardinals when he exited with a knee injury and did not return.

On Monday, head coach Dan Campbell acknowledged Barnes would be "down a significant amount of time." As for a possible placement on IR, Campbell wouldn't go there just yet.

"We’re not going to know that,” Campbell on Barnes being placed on injured reserve. “We’re still getting second opinions on that. What we know right now is he’s going to be down a little while. We know that, and then it’s just a matter of these opinions keep coming back, how long is that going to be? It’s the knee, so is he going to need something done other than one of the ligaments? Can it scar in? Can these ligaments scar in and everything will be good, it just needs time? We know he’s going to need to be down for a little while while the knee heals, and then once it heals, is it going to need surgery?”

Here's a look at the play Barnes got injured on.

Lions LB Derrick Barnes reportedly headed to IR

According to a report from ESPN's Jeremy Fowler Tuesday afternoon, there's a "good chance" Barnes will be placed on IR.

Barnes brings a unique skill set to the Lions' linebacking corps, with the ability to play the SAM role as well as off the ball. They don't have a direct replacement. Jalen Reeves-Maybin and Ben Niemann took some snaps in the SAM spot after Barnes left Sunday's game, but are not greatly suited for the role. James Houston doesn't seem like an option, based on Campbell's words over the last couple weeks. Practice squaders Isaac Ukwu and Mitchell Agude got some run in the SAM role during training camp, and could be options for promotion to the 53-man roster.

Barnes landing on IR is no surprise. Fowler's report should lead to official confirmation from the Lions before too long.

Update, 4:15 p.m. ET: The Lions have placed Barnes on IR.