The ACL Injury

In an unfortunate turn of events, one of the most promising and intriguing sophomore RBs’ seasons ended before it could even begin. On August 28th, 2021, during their final NFL preseason game, Baltimore Ravens’ RB J.K. Dobbins suffered a left anterior cruciate ligament (ACL) injury. The ACL is a ligament in the knee that prevents the lower leg, specifically the tibia, from sliding anteriorly to the upper leg, the femur.

Stats Prior to the ACL Injury

In 2020, Dobbins’ rookie season, he posted the following numbers:

Rushing

134 Rush, 805 Yds, 6.01 Ypc, 9 TDs

Receiving

18 Tgt, 24 Rec, 120 Yds, 6.7 Ypr, 0 TDs

Fantasy Finish

Dobbins played in 15 games and finished as the RB23 with 166.5 FPTS (PPR Scoring).

Rookie Success

Once the Ravens’ 2020 bye week passed, he finally took over the full workload. He averaged 13.64 FPPG with 34 percent of his points coming from TDs (seven) and only 9.5 percent of his points coming from receiving work, which lacked. During this stretch, he looked really good. He looked calm, comfortable behind the offensive line, and patient in between the tackles. The best part of his game was his ability to cut hard and to find yards no matter what the circumstances, averaging 6.01 yards per carry, the best in the NFL for RBs and third for all positions. He carried himself like a true veteran on the football field, despite only being a rookie. This ACL injury will truly impact these two factors moving forward.

The Research: NFL Performance Levels Post-ACL Injury

I had an opportunity to dive into a research study done by Kush Mody and colleagues about NFL players and their performance post-ACL injury. It was a great read and there were a number of interesting findings which I believe can help fantasy football managers. The population of the study was comprised of QBs, RBs, DL, and LBs for a total of 312 participants 

Some of the most important findings are as follows:

• Within the first three years post-injury, players played in fewer games per season?(8.7 vs 13.7; P < .0001) compared with pre-injury (Mody, 2022)
• Players started in fewer games (3.0 vs 8.3; P < .0001) compared with pre-injury (Mody, 2022)
• Players had lower AVs (approximate values) (1.5 vs 4.3; P < .0001) compared with pre-injury (Mody, 2022)
• Players had decreased snap counts (259.0 vs 619.0; P < .0001) compared with pre-injury (Mody, 2022)

Additionally, only 55.8 percent of the study’s participants returned to play (RTP) and only 28.5 percent of the RTP players lasted three or more years in the NFL. Based on all of the study’s findings, it is clear that ACL injuries do impact the performance of NFL players after they recover.

Here are a few examples of other well known NFL RBs and their results: (Dalvin Cook, Todd Gurley III, Edgerrin James)

Redraft & Dynasty Fantasy Outlook

A friend of mine, Jeff Mueller, DPT (Doctor of Physical Therapy), was kind enough to let me look at and use some of his charts for this article.

“There is usually a 12-15 percent FPPG drop from pre-injury to post-ACL injury. This means that rushing production significantly lessens a year after an ACL tear.”

Jeff Mueller, 2022

Combining that and a minimal receiving role, Dobbins could have a very difficult time creating significant fantasy points.  However, there are a few hopeful tidbits on this situation. Dobbins is still young (23), his ACL injury was isolated, and he will have a little under a whole year to fully recover. He also has a very minimal injury history and a durability grade of five (five being the most durable). Unfortunately, this is the end of the list. There are far more negatives connected to data and previous history with performance post-ACL injury.

Because rushing production significantly drops off after returning from an ACL injury, that means a majority of FPTS has to come from receiving work. As mentioned earlier, Dobbins had a very small amount of receiving work, only 9.5 percent of his FPTS. Not a recipe for fantasy football success.

Post-ACL Injury Performance Myth

Ravens’ GM Chimes In On ACL Rehab Progress

So, what can we see production-wise in the future from Dobbins? Well, from the data discussed earlier in the article, we can expect a down 2022 season from Dobbins in every facet of his game. Even if he did have a more profound receiving role, it would still be a bleak scenario in Baltimore.

“He obviously suffered a serious knee injury but he’s a young player, a hungry player, he’s got a great mindset and he’s been working very, very hard. We are very, very confident he’ll come back and be the type of player that he was two years ago [his rookie season].”

Ravens’ GM Eric DeCosta

Later he also goes on to add:

“I would see him a lot and I would also see him at the facility during his rehab. Very confident that he’s going to come back and really flourish this year.”

Ravens’ GM Eric DeCosta

One Final Thought

If my calculations are correct for Dobbin’s FPPG and ADP, based on the 12-15 percent performance drop-off, his 2022 season will be disappointing. The drop-off compared to RB finishes in 2021 and 2020 puts him at ~RB34 and ~RB32 respectively. Dobbin’s ADP is currently sitting at the 53rd pick overall and the RB22. The highest he has been picked in a draft has been 28th overall (RB14) and the lowest he has been picked in a draft has been 71st overall (RB26). In my opinion, he is being over-drafted and is overrated for the 2022 season. I would be looking to sell him.

A reminder for you: more great NFL and fantasy football coverage can be found on the Belly Up website, as well as fun, informative content on the Belly Up Podcast Network & Belly Up TV. Make sure to check back in with Belly Up Fantasy Sports for more fantasy analysis and injury analysis to ensure you are a championship-winning fantasy manager. Got a question or have something to say? Leave a comment below and follow me on Twitter @TFFPhilip and Instagram @thrillsfantasyfootball.

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References

ACL Tears of NFL Players. Adapted from “ACL Tears” by Jeff Mueller, DPT, 2022, April 13.

Mody, K., Fletcher, A., Akoh, C., & Parekh, S. (2022). Return to play and performance after anterior cruciate ligament reconstruction in national football league players. Orthopaedic 
Journal of Sports Medicine, 10(3), 1-8. https://doi.org/10.1177%2F23259671221079637