Dissecting De’Aaron Fox’s grade 3 ankle sprain, “indefinite return” & three timeline scenarios

Kings guard De’Aaron Fox rolled his ankle inwards (inversion) on 11/11 during a 5v5 halfcourt practice drill, limping off without being able to bear any weight on the ankle. He was immediately taken for x-rays which showed no fractures and the team eventually diagnosed him with a “grade 3 inversion sprain”.

The team has set the dreaded “indefinite return” timetable with De’Aaron telling us that he’ll be re-evaluated in three weeks and then playing it by ear depending on the results.

In this piece, I’ll detail the collective factors that helped determine Fox’s grade 3 diagnosis – they may not be as black and white as you think – and shed light on De’Aaron’s hazy, return to play (RTP) timeline by breaking down the three most likely scenarios.

If you prefer a video format, here you go:

The injury and diagnosis


An inversion (inwards) ankle sprain stresses two lateral (outer) ankle ligaments, the anterior talofibular ligament (ATFL) and calcaneal fibular ligament (CFL).


Ankle sprains are classified into three grades with increasing severity: Mild grade 1 tear, moderate grade 2 tear, and a severe grade 3 complete tear.

Diagnostic factors

However, these grades aren’t cut and dry because diagnosing ankle sprains is an inexact science.

For example, the research shows that taking an MRI – which is typically the gold standard for many soft tissue injuries – is accurate only 79% of the time when it comes to diagnosing a complete tear of the ATFL whereas it’s 95% accurate for an ACL or meniscus tear.

Accordingly, the diagnosis of ankle sprain severity relies on multiple indicators, or as I call them “drops in a bucket”. The collective factors for Fox’s grade 3 sprain include:

A. Near total loss of function

We know that De’Aaron was unable to bear any weight on the ankle after the injury occurred.

B. Manual examination

Findings during Fox’s manual exam most likely included extreme extreme point tenderness, severe hemorrhaging (bruising), a decrease in total ankle range of motion greater than degrees, swelling and edema measured greater than 2 cm, a positive anterior drawer test which indicates involvement of the ATFL ligament and, a positive talar tilt test which indicates involvement of the CFL ligament.

C. Imaging

Imaging would include an MRI and stress radiograph which is an X-ray taken while a member of the medical staff performs the anterior drawer test I mentioned before.

If the latter shows gapping of the ankle mortise less than 3cm, the injury is termed a grade IIIa tear whereas if the gapping is greater than 3cm, the injury is termed a grade IIIb tear.

This distinction is important because there’s research showing that a grade IIIa, on average, takes 15 days less to come back from compared to a grade IIIb.

Based on De’Aaron‘s three week post injury re-evaluation date, my educated guess is that he has a IIIa tear. Speaking of re-evaluations and return to play timelines…

Fox’s return timeline scenarios


Fox’s re-evaluation in early December will consist of re-examining the previous factors and – very importantly – evaluating for overall ankle stability by taking him through the Star Excursion Balance Test (SEBT) which evaluates side to side proprioception, dynamic postural control, strength, and mobility.

Guarding against ankle instability is a critical piece of ankle sprain return to play because if left unchecked, it could lead to Fox developing chronic ankle instability (CAI) which comes with a whole slew of long-term problems including persistent pain, discomfort, swelling, loss of ankle range of motion, decreased function, and feelings of instability and fear of movement or re-injury (kinesiophobia). 

The results from the re-evaluation will dictate Fox’s return to play timeline. Here are the three most likely scenarios:

Scenario #1

If De’Aaron’s ankle pain/discomfort has decreased significantly and the testing goes well with minimal signs of instability, he’d likely be cleared for the return to play protocol and bring ramping up activity.

If everything progresses as expected, I’d expect around a 10 day ramp-up period for a total return to play timeline of roughly 4.5 weeks. 

Scenario #2

If De’Aaron is still experiencing moderate pain and shows some signs of instability, the team could wait until the 6 week mark and then re-evaluate. If at that point the pain and instability continue to persist, the research says a lateral ankle ligament reconstruction is then indicated.

Scenario #3

If Fox has severe pain & numerous signs of instability at the three week re-evaluation and/or he also has a osteochondral defect (OCD) aka the force the ankle sprain also chipped off a piece of the cartilage in his ankle joint, the team could decide to pull the plug and have surgery immediately.

That being said, the orthopedic surgeon I consult with on surgery related topics told me that this would be a very aggressive approach and the least likely to happen. He said that unless there’s a large OCD lesion, it’s very unlikely the Kings medical staff wouldn’t give Fox until at least the six   == week mark for another re-assessment and then decide his fate.

A common confounding variable

Even if the re-evaluation goes swimmingly, there’s one common setback that could manifest during Fox’s rehab and delay his timeline: A “bone bruise”. These usually don’t show up on imaging until weeks after the initial twist (and only on MRI to boot) and will only pop up on the  rehab team’s radar after the athlete feels persistent pain in the ankle after ramping up weight-bearing activity.

A prime example of this is former Lakers guard Lonzo Ball who suffered a grade 3 inversion sprain last season on 1/20/18, was tracking very well to be back in roughly five to six weeks, but then, after having prolonged pain following treadmill running, had a follow-up MRI that showed a bone bruise in his ankle. These can last for awhile and to that point, Zo wasn’t cleared for full on-court activities until nearly 7 months after his initial injury.


The research definitively shows that the biggest risk after an ankle sprain is another ankle sprain.

To combat that, the medical team will continue to incorporate proprioceptive training into Fox’s training plan and very likely would use an external support – such as a lace-up brace or taping.

Both proprioceptive training and external supports have been shown repeatedly to reduce ankle sprain re-injury risk. However, I always recommend only using external supports for the short-term because it changes ankle and foot mechanics, leads to dependency, and mild decreases in athletic performance.

All in all

All in all, De’Aaron faces an uncertain return timeline after his grade 3 sprain. Depending on the re-evaluation and ramp up process, he could be back as soon as four to four and a half weeks to missing six to eight weeks to needing surgery and being out for the entire season. That variance is an inherent and unfortunate reality for the player, team, and fans alike.

That’s a wrap for this video. Thanks for watching. My goal is to provide you with in-depth, evidence based, narrative free analysis and you can always find me on IG and Twitter @3CBPerformance. Make sure to sub to the channel for the latest updates. 3CB out.

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