ESPN, October 11, 2023
For years, the grass field at Nissan Stadium in Nashville was a mess. It was loose in some areas and barren in others, and it got increasingly slippery during the Tennessee Titans‘ regular season. Worse, according to data collected by the NFL and the NFL Players Association, there was a higher rate of noncontact injuries to the lower extremities on that grass field than on artificial turf in some NFL stadiums.
So the Titans, along with the local governments that own the stadium, made a decision they said would improve safety and would be supported by the data. Before the start of the 2023 season, they converted the playing surface to a version of monofilament synthetic turf called Matrix Helix.
“From an injury prevention perspective, that was a logical decision to make,” said Jeff Miller, the NFL’s executive vice president for communications, public affairs and policy.
The verdict rankled the NFLPA, however, and left the NFL and Titans to explain why turf — long associated with higher injury rates and elevated wear and tear on players — was the best option. It also illustrated the complex nature of an increasingly public issue between the league and its players, one that arises every time a prominent player suffers a significant injury on turf. There have been several recently, including Buffalo Bills star linebacker Matt Milano suffering an injury to his right leg Sunday that will require surgery.
After New York Jets quarterback Aaron Rodgers tore his left Achilles on the turf at MetLife Stadium on Sept. 11, NFLPA executive director Lloyd Howell called on owners to convert all 30 stadiums to grass. In subsequent interviews with players, league and union officials, along with unaffiliated experts, ESPN worked to understand whether Howell’s request is a possibility, why the two sides are interpreting their shared data so differently and whether plans for the 2026 World Cup will provide a more agreeable way forward. It’s a topic that transcends data for players, who notice a dramatic difference in how their bodies react on different surfaces.
The NFL says improvements in turf technology have closed the gap on noncontact lower extremity injury rates and revealed last year that the rates during the 2021 season were statistically even. But as the NFLPA pointed out months later, the gap increased during the 2022 season (.048 per 100 plays on turf in 2022, .035 on grass).
NFLPA president JC Tretter said “it shouldn’t be this hard” and believes it is “pretty obvious” grass would protect players best wherever it is possible.
“We feel the data has proven our point,” Tretter told ESPN. “We feel the player opinion is consistent. There are, really, only two bodies of people that are disagreeing at this point with us: People who manufacture turf and the NFL. And that’s a frustrating spot to be in.”
Half of the NFL’s 30 stadiums feature grass, and the NFLPA would like the remaining 15 to switch. But improvements in turf technology, as well as climate and ownership factors, make the discussion more layered.
But grass remains the clear preference of players, despite the data set cited by the NFL in guiding the Titans’ shift from grass to turf. The NFL, however, does not release injury data about specific stadiums to the public.
The safety statistics are generated through the Field Surface Safety and Performance Committee, a group mandated by the collective bargaining agreement that meets twice yearly and includes experts selected by the NFL and the NFLPA, in addition to their respective medical officers. To help identify injuries potentially caused by the playing surface, the committee focuses on noncontact injuries suffered in the lower extremities. In each of the past 11 years, the injury rate has been higher on turf, although in 2021 the figures were close enough that the difference was statistically insignificant (.042 per 100 plays on turf, .041 on grass).
The NFLPA called the 2021 data an outlier, and players are becoming increasingly outspoken on this topic.
NFL officials don’t dispute the relevance of the data on playing surfaces but say it represents only a portion of a more holistic approach to reduce lower extremity injuries, one that includes better equipment, smarter training habits and better monitoring of exertion levels.
“Our goal is to reduce lower extremity injuries, period,” Crandall said. “And we need to do that on all surfaces, regardless of what it is.”
Tretter, who played eight years as an NFL offensive lineman, remembers being hooked up to an ice machine to relieve the pain from playing on turf.
“I knew playing the week after was going to be extra difficult because of the wear and tear and the pounding my knees were going to take on turf,” he said. “And then I’d look at the worst-case scenario: A turf game [on Sunday], and then if that Thursday we had to play a game and that was turf, too.
There will be seven NFL stadiums that currently use turf hosting the 2026 World Cup, and as a condition to host, those stadiums will install grass for the tournament. The NFLPA believes that shows it’s possible to have grass full-time in those stadiums. Alex Slitz/Getty Images for Premier League
Bad grass vs. good turf
Mark Drakos is an orthopedic surgeon at the Hospital for Special Surgery in New York and an assistant team doctor for the New York Knicks and the New York Mets.
Drakos’ research found grass is best for players’ health, particularly when it comes to ankle and noncontact knee injuries. He said: “The data is pretty conclusive.” He also said turf is stickier and less forgiving, which can cause the foot to catch and send torque up to the knee.
This year, the American Journal of Sports Medicine examined 53 studies, across all sports and levels of competition, published from 1972 to 2020. Twenty-five of them compared foot and ankle injuries on different surfaces, and 32 examined knee injury rates on synthetic turf and on grass. In summary, they found that there are “a higher rate of foot and ankle injuries on artificial turf compared with natural grass on both old- and new-generation turf,” and that “elite-level football athletes” were more predisposed to knee injuries on synthetic turf. The AJSM said there were “a few” studies that sided with turf on overall injury rates.
“The artificial turf industry has been vehement,” said Diana Zuckerman, president of the National Center for Health Research, “and they’ve made a lot of money claiming that their product is perfectly safe, and there’s really growing evidence that that’s not true. And it’s clear that even in the most recent types of artificial turf … the accidents are still more likely to occur.”
“Guys get really, really frustrated when those teams pitch the idea that it’s too hard to grow grass,” Tretter said. “If you can grow grass in Green Bay, Wisconsin, you can’t tell me in Tennessee you can’t handle it.”
The NFLPA believes if grass can be grown and played on without issue in Green Bay, Wisconsin, that can happen anywhere. The Packers typically limit themselves to one non-Packers event on the field per year.
“When the World Cup comes around,” Tretter said, “and these teams and these owners will roll out green grass for the European soccer teams to play on, and then replace it right back with turf for the employees, I feel like it’s going to be a damning moment for this league because it will show you exactly how decisions are made. Decisions are made about how they can bring in money, and if they need to put in grass to make money, they will. And if they’re going to roll out turf to make money, they’ll do that.”