Through two weeks, two of the top quarterbacks in the NFL have been sidelined by toe injuries. San Francisco 49ers quarterback Brock Purdy missed the team's Week 2 win over the New Orleans Saints and could miss multiple games after he suffered the injury in the team's season-opener in Seattle. In Week 2, Cincinnati Bengals quarterback Joe Burrow went down in a home win over the Jacksonville Jaguars and needs surgery that will force him to miss at least the next three months.

In both cases, the injuries are a version of turf toe. But what exactly is turf toe?

The injury is described by the Cleveland Clinic as a hyperextension of the big toe. It occurs when the toe remains on the ground while the heel is lifted in the air, causing soft tissues and ligaments in the big toe to stretch or tear. It can also occur from too many repetitive movements over a period of time or a sudden trauma.

There are three grades for turf toe. A Grade 1 turf toe is when the soft tissue is stretched but not torn. A Grade 2 injury is when the soft tissue is partially torn while a Grade 3 level is when the soft tissues are completely torn and the metatarsophalangeal joint, the larger of two joints in the big toe, may be dislocated.

The recovery time for the injury depends on the severity. A Grade 1 turf toe can be resolved in as quickly as a week, while a Grade 3 injury that requires surgery could require up to six months. Typically, turf toe requires time and rest to heal, with surgery being an option for severe cases. Most athletes with this injury do make a full recovery.

Burrow's injury appears to be more severe than that of Purdy, who could return in the next few weeks, with coach Kyle Shanahan even saying Sunday that "there is a chance" he could play next Sunday against the Arizona Cardinals. But Burrow's injury will require surgery that will keep him out at least three months, a league source confirmed to The Athletic's Dianna Russini.

After he suffered the injury, Burrow needed assistance getting from the medical tent on the field to the locker room. After the game, he was seen walking through the locker room in a walking boot with crutches. After gathering a second opinion Monday, the decision was made to undergo surgery with hopes of a late-season return.

Cincinnati coach Zac Taylor is expected to provide more information Monday afternoon.

Shanahan initially offered little information about Purdy's injury after he suffered it in San Francisco's season-opening win in Seattle. When asked if it was turf toe, he replied: "Just toe. That's all I've got here."

Amid persistent questions throughout the week, he shed a little more light on the ailment. Asked if it could be described as turf toe, he said, "If you want me to."

"It's a generic thing for anything on the bottom of the big toe," Shanahan continued. "Since it's halfway between the side and the bottom, that's why we don't say turf toe but it's the third time you've asked me, so I'll call it turf toe for you, if you want."

Turf toe injuries have become more prevalent in football since the playing surface shifted from natural grass to artificial turf. Artificial turf is easier to maintain but is a harder surface, relative to natural grass, and therefore less forgiving and makes for less flexibility when players attempt to push off with their feet.

Burrow's injury occurred at home at Paycor Stadium, where the Bengals play on synthetic turf with slit-film fibers. Former NFLPA president JC Tretter previously called for a ban on slit-film turf due to concerns for player safety. Purdy's injury occurred at Lumen Field, where the Seahawks play on FieldTurf Revolution 360. Lumen Field is set to co-host the 2026 FIFA World Cup, which will require at least a temporary change to natural grass next year.

What is turf toe? Explaining the injury sidelining NFL QBs Joe Burrow, Brock Purdy