Gronkowski is one of the most explosive players in the NFL having racked up just about a touchdown a game over a 4 year span. After undergoing back, forearm and ACL surgery in 2013 there are two big questions that need to be answered before going into this year’s draft:
1. Risk: Will Gronkowski make it through enough of a season in 2014 to make it count?
2. Performance: What can we expect from his performance returning from an ACL surgery?
Gronk has a high risk of getting injured this year (Rob Gronkowski’s injury history here). The fact that the back surgery he had last year was to relieve symptoms of a similar injury that laid him out in college is red flag. Any time a player has plates and screws in his body it increases risk of injury as well – especially in a body part like the forearm that is used by Tight Ends for blocking and swatting off 300lb linebackers.
It is rare for ACL’s to reoccur, however his ACL tear happened right at the end of 2013 which means he is in the early part of the 6-9 month recovery window that most athletes need to rehab before getting back on the field. The probability of injury arrow is definitely pointing up and there is a good chance that he will get injured this season. How severe it will be is hard to say but you should count on him missing a few games this season. Knee swelling, pulled hamstrings and ankle injuries are usually what follow the year after an ACL injury and this is heightened by the shortened recovery period he has had.
In trying to understand what his performance will look like we are going to base our projections on the research study titled: Outcomes of Anterior Cruciate Ligament Injuries to Running Backs and Wide Receivers in the National Football League. This paper was written in 2006 and studied a group of 24 NFL athletes (14 RBs and 10 WRs) who suffered from ACL injuries from 1998 to 2002.
In order to measure performance pre and post ACL injury they used a metric called “Power Rating” (PR) that is based on the following equation:
Power Rating = (Total Yards/10) + (touchdowns X 6)
In short they found that Running Backs returning from ACL injuries suffered a drop in power rating per game from 11.7 to 8.0 (-32%). Wide receivers who returned from an ACL injury experienced a decline in power rating from 7.7 per game to 4.6 (-41%).
For the sake of this article we will consider the TE position to be the same as the WR by focusing our comparative analysis on TEs who are used primarily as receivers and not inline blockers. The study used 3 year averages to establish a baseline so for the table below we look at TEs who were active in the same period to get an idea of power ranking and we also included some TEs who broke out last year to give an idea of context where the Gronk post ACL would fall.
2011- 2013 Elite Tight Ends Power Rating
Gronk post ACL injury (Power Rating -41%) and where he would fall vs the top 5 TEs of 2013
Ultimately it doesn’t look good if Gronkowski is going to end up just outside the top 5. This plus his risk factor as outlined above would place him as a high risk/low reward option for redraft purposes.
A caveat to these numbers are that this study was done on injuries and surgery that was done over 10 years ago. Surgery practices along with the science of rehab have improved to a large extent since then allowing for players like Adrian Peterson and Jamaal Charles to return to the game and pick up as dominant as they left off. According to Dr Klapper who hosts the ESPN Weekend Warrior show Adrian Peterson has changed the bar for recovery from ACL surgery and we may see another version of that if Gronk comes back to dominate this season.
The biggest question that will need to be answered on draft day is what your strategy is with regard to risk. On the surface Gronk’s risk/reward profile does not meet the current ADP he is at (3.08 courtesy of Draft Sharks ADP tool). However if you’re open to risking a 3rd round pick on the return of the old, pre-ACL Gronk you should make plans on hedging that risk elsewhere by avoiding risky Running Backs and Wide Receivers.