Carson Wentz and the ACL Return Timetable

by Scott Kacsmar

Concussions draw the headlines in NFL injury news these days, but a torn anterior cruciate ligament (ACL) in the knee is still a big deal. A torn ACL almost always means a player's season is over, but what are the concerns for the following season? Recovery time for these injuries is generally viewed as six to nine months.

Roughly 50 players tore their ACL in 2017. The biggest name on that list is Carson Wentz, the starting quarterback for the defending champion Eagles. Wentz tore his ACL in Week 14 last year before the Eagles finished 5-1 with Nick Foles starting in his place. We are exactly one week away from opening night kickoff in Philadelphia and Wentz has not been cleared for contact yet. He has been cleared for 11-on-11 practice, but not contact, and he did not participate in the three preseason games. While it seems unlikely that Wentz will land on the PUP list, which would require him to miss at least the first six weeks of the season, there is a growing possibility that he misses a couple of regular-season games.

How common of a timetable would that be for someone coming off an ACL injury so late in the season? With help from our injury expert Zach Binney and the Football Outsiders injury database, we prepared some data.

A couple of notes about the injury numbers we are using here. First, since we are interested in seeing when a player returned to action, we wanted to make sure we were looking at players of a higher caliber. An undrafted free agent who tears his ACL in July may have just watched his NFL dream wash away. So we limited our data to just the players we marked as starters or key reserves in the season they tore their ACL. This does not mean they were going to be starters or key reserves the following season, but they were at least coming back from a role of importance. This also means no kickers or punters were studied.

The other clarification is that this data does not include players who tore their ACL during the playoffs, such as Tennessee's Jack Conklin this past January. Frankly, our playoff injury data is not up to the standards of our regular-season data that is used to calculate AGL, so we were not able to include those few players that would have added to the list. That would include Jeremy Lane, who tore his ACL in Super Bowl XLIX for Seattle and wasn't able to return to action until Week 12 in 2015.

In the end, we studied 112 players with a torn ACL suffered in the 2011-2016 regular seasons. Sixty-one of those players (54.5 percent) were active in Week 1 the following season, while 51 were not. The following table is a comparison between those two groups of players, including splits for age and the week the torn ACL occurred.

The key, logical finding was that the players who were slower to return saw their ACL injury occur almost two weeks later than those who returned quickly. The Week 1 inactives were also on average a half-year older, but "old age" wasn't too significant of a factor. Of the 19 players who were 30 or older, 10 of them were ready by Week 1 the following season, which is right in line with what happened to players aged 25-to-29. Younger players aged 21-to-24 were available Week 1 more often at 62.1 percent.

The splits for when the injury occurred produced some interesting results. Whether it was an injury that occurred before the season or one that happened in the first five weeks, the players were ready for Week 1 about 63 percent of the time. When it happened in Weeks 6 to 10, then that dropped to a 50-50 proposition. In the final seven weeks (the Wentz situation), the player only returned to Week 1 action 37.5 percent of the time, or roughly the reverse of the rates from early in the season.

Given that a torn ACL used to be thought of as a career-ending injury, this is somewhat comforting. On the other hand, if almost half the time the player isn't ready for action in Week 1, then that is still a concern. But what if the player is ready for Week 2 or 3, which could be the case for someone like Wentz? We broke down our 51 players who missed Week 1 into four groups to get a better understanding of why they weren't ready for the season opener. We'll go through the groups in order from most serious situations to the least serious.

Note: the "Year" and "Age" is listed for the player for the season when he tore his ACL. The "Wk ACL" is the week of the season when he tore his ACL. A "0" means it happened prior to the Week 1 opener.

If we think of the 14 players who played in the preseason as being healthy enough to play in Week 1 had they been needed, then that would bring the Week 1 active rate post-ACL up to 67.0 percent. So it might be better way to think that about two-thirds of the players returning from an ACL injury in 2017, including Wentz, will play in Week 1.

We'll leave you with a list of 16 notable 2017 players, minus Jack Conklin, coming off a torn ACL and what their status has been this preseason.

Wentz and Tyvon Branch (free agent) were the only players listed who were injured in Week 10 or later last season. DeAngelo Hall retired this offseason. Of the 14 players still on active rosters, nine played in the preseason. In addition to Wentz, the Eagles have also held Jason Peters and Darren Sproles out of August games, but both seem more likely to play against Atlanta next Thursday. Green Bay tackle Bryan Bulaga and Arizona linebacker Markus Golden are in danger of not being ready for Week 1, but they have a few more days to prepare than Wentz does.

Obviously the timing and severity of an ACL injury will have an impact on when a player can return to action. Carson Palmer once infamously tore his ACL in a wild-card playoff game against the Steelers, and he was ready to go in the 2006 preseason. However, practically no one could have endured the type of injury that tight end Dustin Keller suffered in the 2013 preseason and gone on to a normal playing career. Keller not only tore his ACL, but also his MCL and PCL, and also dislocated his knee.

Thankfully, no one coming back this year has that big of a hurdle to overcome. But when a fan says they don't want to rush a player back from an ACL injury to jeopardize the rest of his career, there is something to be said for that given several of the names we looked at. The Eagles want Wentz on the field for a long time. In the grand scheme of things, next week (and the week after that) isn't that important. It also helps when Nick Foles has shown he can handle a few games just fine.