Heading into this season, the Boston Celtics re-vamped their entire roster, adding new talent via the 2017 Draft and free agency before making the blockbuster trade that netted them Kyrie Irving.Without a doubt, their free agent prize was Gordon Hayward, an emerging star who averaged 21.9 points, 5.4 rebounds and 3.5 assists per game last season for the Utah Jazz.Reuniting with his collegiate coach Brad Stevens, Hayward was slated to help lead a young Celtics roster, signing a four-year, $128 million maximum contract.Note the past tense as all of that has now come to a screeching halt.With 6:45 left in the first quarter in the season-opener against the Cleveland Cavaliers, Hayward went up for an inaccurate ally-oop pass, collided with LeBron James on his way down and landed awkwardly in a heap of pain.Immediately, teammates, Cavaliers players, broadcasters and the crowd held their breath in stunned silence as Hayward screamed in pain at the sight of his left ankle, which was displaced at an odd angle as the result of the play.LeBron and Dwyane Wade were among the Cavaliers players who appeared most appalled by the injury.

The Celtics huddled, appeared to say prayers and hugged each other. Irving was seen visibly sobbing into the arms of teammates Marcus Smart and Jayson Tatum.

Below is a look at what happened. Please note that this will be hard to watch. Out of respect for Hayward, here is the edited, zoomed-out version of the injury:

As soon as his left leg was immobilized in an air cast, Hayward was lifted up onto a stretcher and wheeled off the court to a standing ovation from the Cleveland crowd. Right before he was wheeled off, LeBron went over to shake his hand.

According to ESPN’s Chris Forsberg, numerous doctors as well as front office staff of both teams were with Hayward in the Cleveland locker room where he underwent X-rays that confirmed a broken ankle.

The injured Isaiah Thomas, who recruited Hayward to the Celtics before he was traded away this summer, left the Cavaliers bench briefly mid-game to check on his friend. LeBron reportedly visited briefly after the first quarter as well, leaving the bench to head into the locker room.

Celtics assistant GM Mike Zarren and co-owner Steve Pagliuca were at Hayward’s side throughout the process according to Forsberg.

In a game that was originally presumed to feature a lot of hostility, Hayward’s injury led to a universal feeling of sadness for everyone on the court, in the stands, and watching at home.

As you might imagine, a number of high-profile athletes sent their condolences to Hayward via social media immediately after witnessing the horrific injury. Paul George, who suffered a similarly-horrifying injury a few seasons ago, was among the first to send his prayers.

John Wall put aside his rivalry with the Celtics for a second.

Steph Curry sent his regards before his game tipped off as well.

NFL star JJ Watt, who is nursing his own injury at the moment, also chimed in.

Many other notable athletes across all sports extended their sympathies as well.

In regards to the injury moving forward, here’s what we know at the moment.

First, Hayward will reportedly be receiving treatment in Boston.

Secondly, this injury is different than the one that Paul George famously suffered, as there is ligament damage present.

Despite that, a doctor has put his reputation on the line by hypothesizing that not only will Hayward return this season, but he will be back in 4-to-5 months.

Apparently he believes that 6-to-8 weeks after surgery, Hayward will be able to begin working out again since he’s a world-class athlete. The doctor mentioned that his cutting ability might be slightly compromised, but that was certainly a surprising prediction to hear based on the optics of the injury.

Hayward logged two points, a rebound and a foul over his brief time on the court. Marcus Smart subbed in for him as the team must prepare to now spend a large portion of the season without one of their best players.

According to ESPN’s Bobby Marks, the Celtics will be eligible to apply for the Disabled Player Exception based on the injury. The exception is reportedly worth $8.4 million and Boston would have until March 10 to use it. Therefore, Danny Ainge will have an opportunity to sign, claim or trade for a player that has one year left on his contract since there was already an open roster spot before the injury occurred.

Regardless, it was a terrible way to start the year for Boston.