Arizona Cardinals running back James Conner is headed to the IR after suffering a knee injury in the Week 5 loss to the Cincinnati Bengals, and his absence creates quite an issue for fantasy managers to tackle moving forward. With Conner out for at least the next four weeks, filling his running back spot is going to create some challenges, especially with the Bye weeks here and robbing teams of depth.

How should fantasy football managers go about replacing Conner's production? And what should Conner managers do in season-long and dynasty leagues? Let's break it all down.

Replacement options in the Cardinals' backfield

Replacing a talented player like Conner won't be easy. He runs hard between the tackles with his physical nature, but he was also a solid receiver out of the backfield. Conner wasn't being used as a receiver nearly as much as previous years (8 receptions through five games), as the Cardinals have recently opted to use Emari Demercado as the preferred passing down back with Keaontay Ingram inactive the last two weeks with a neck injury.

Ingram came into the season as Conner's backup, but has been woefully ineffective. Ingram has 12 carries for 15 yards and just one reception on the season, while Demercado has made the most of his opportunities over the last few games. The undrafted free agent out of TCU has 14 carries for 48 yards and a touchdown, in addition to 6 receptions for 40 yards.

It's important for fantasy football managers to note that the Cardinals clearly trust Demercado as a pass protector. That's a big deal for a team that's going to be playing from behind a lot. While the Cardinals did sign Tony Jones Jr. from the New Orleans Saints this week, he's a between-the-tackles thumper who could potentially be used in short-yardage situations more than anything else.

The Cardinals could potentially trade or sign another running back, but rebuilding teams don't invest draft capital in short-term fixes at the cheapest spot to acquire talent.

Emari Demercado has flashed enough to get a chance to be the Cardinals' lead back in Conner's absence and should be the top priority waiver wire addition this week at running back. He'll be a low-end RB2/Flex candidate with a bump in PPR leagues against two explosive offenses in the next two weeks in the Rams and Seahawks.

James Conner, Cardinals, James Conner Fantasy Football

What to do with Conner in fantasy football leagues? 

With the actual knee injury itself still unknown, you need to hold on to James Conner for the time being. So long as there isn't any surgery done, Conner has a good chance to come back once his 4-week IR stint is over, and there's still plenty of football left to be played. Finding running back talent on the waiver wire is always difficult, but keep Conner at least until more information about his injury timeline becomes available.

If Conner was dropped in your league, he's worth a bench stash even through the bye weeks. It's hard to find steady RB2 options, and Conner has consistently been that throughout his career. Even if Emari Demercado pops, Conner would likely take back his early down role and still have value once he's off the IR.

James Conner is an interesting buy candidate in dynasty leagues. At 28 years old, there may not be a whole lot left in the tank. But given that we know Conner will be out for the next four weeks, a fourth or fifth-round future pick may be enough to snag him from a manager who is looking to replace him and needs a roster spot. This kind of speculative add could pay dividends once we get into the fantasy postseason, especially if the Cardinals don't get solid production from any of Conner's replacements while he recovers.

For fantasy football purposes, Conner is a hold until more information becomes available. He still belongs on rosters in all leagues.