The Lions used their game against the Bills as their regular season dress rehearsal, which is a common practice in the NFL. Unfortunately, two of their starters may not dress for the parts of the regular season now. Their 2017 and 2018 first-round picks, Jarrad Davis and Frank Ragnow, both went down with lower leg injuries during Friday night’s exhibition.

While we have already received relatively good news on Ragnow’s injury, we’re still pacing the waiting room with regards to Davis, although coach Matt Patricia has said he won’t be considered for injured reserve.

To gain some insight into Davis’s mystery injury, I spoke with my friend and colleague John Verros, who serves as the Injury Coordinator at Sports Info Solutions. John is a Michigan native and reluctant Lions fan who graduated with an M.S. in kinesiology from the University of Michigan. He is tasked with diagnosing hundreds of injuries each week for the company’s team and media clients. He also correctly diagnosed Ragnow’s injury, provided this scoop from Ian Rapoport is accurate.

BR: Thanks for taking the time to talk with me, John. Could you start by detailing the range of outcomes for Davis following his injury last night?

JV: Based on the injury mechanism [how it occurred], Davis is most likely dealing with a high ankle sprain. In the limited amount of time the broadcast showed the training staff evaluating him on the bench, you could also see them examining his Achilles tendon, which means an Achilles strain could be in play, as well. However, I don’t see an Achilles tear as likely after watching him walk around on the injured leg on the sideline.

There were also reports that they were conducting an MRI on his foot. I don’t think it’s impossible that he suffered a Lisfranc fracture based on the video, but I think it’s unlikely that he suffered a fracture based on the fact that we haven’t had any news yet. A mild foot sprain – similar to the one Cam Newton suffered – is possible but seems unlikely due to the mechanism of the injury.

It should be noted that the chronic outlook of a foot sprain/fracture would be less optimistic than that of a high ankle sprain.

BR: If it is indeed a high ankle sprain, what’s his timetable to return and what would be some potential complications if he came back too soon?

JV: It depends on the severity. If it’s a severe high ankle sprain, it may require surgery. At that point, you’re looking at Davis being a candidate to return from IR later in the season.

The best-case scenario would be a return to action in Week 3 against Philadelphia, but that would be rushing things, in my opinion. While it’s possible to return from this type of injury after several weeks, it means playing through instability in the ankle and lower leg.

It’s important that the Lions training staff makes sure he doesn’t appear to be favoring his right side when he runs, stops, cuts, or jumps. Any deviation in his normal gait could lead to a reinjury of the ankle or an injury of an area that is overworking to compensate for the weakened ankle.

Although there’s currently no research to support this, there’s a theory that the calf muscles on the injured side work overtime to support the ankle joint. Any deviation from his normal movement patterns will result in the kinetic chain being altered. This means his knees and hips will have to bend, twist, and provide power in a new movement pattern. It’s crucial that the Lions test Davis and correct any imbalances before he returns.

At any rate, I would expect Davis to be limited in his ability to change directions for the next couple of months.

BR: What are Davis’s options for surgery, should he require it?

JV: If the ankle syndesmotic ligament is torn (as it might be in a severe high ankle sprain), surgery is a logical option to pursue.

Prior to a few years ago, surgeons most commonly used screws to fixate and provide stability of the tibia to the fibula. However, a surgery called the ‘tightrope’ procedure is becoming more popular. Surgeons slip a strong suture through small holes in the bone; fasten it with small, metal buttons, and then tighten it as you would a zip tie. This allows for early restoration of ankle stability, motion, and function. It also cuts the recovery time from a high ankle sprain from six-to-eight weeks down to four weeks. Notably, the University of Alabama had both Jalen Hurts and Tua Tagovailoa undergo this procedure.

BR: Would you expect a high ankle sprain to be a chronic problem for Davis, regardless of whether or not he has surgery?

JV: I would expect the change of direction ability of a player with a high ankle sprain to be limited for several weeks, especially if they’re playing through pain. However, it shouldn’t affect him chronically and the risk of recurrence goes down as the time to recover is increased. The long-term effects of the injury should be minimal.

You can follow John on Twitter @VerrosJohn.