The Boston Celtics are in trouble.

Five minutes and 15 seconds into the 2017-18 NBA season, prize free-agent signing Gordon Hayward dislocated his ankle and fractured his tibia, turning what was supposed to be an enjoyable night – and season – into a nightmare scenario for the Celtics.

Hayward, 27, signed a four-year, $128 million contract with Boston this summer, reuniting him with former college coach Brad Stevens. Hayward claimed his reason for leaving the Utah Jazz after seven seasons was that the pair had “unfinished business” following a national title appearance with Butler in 2010.

“All of these years later, we still have it,” he wrote. “And that’s to win a championship.”

Those title dreams have been put on ice along with Hayward’s ankle after a brutal break that left those watching visually disturbed (i.e. Paul George, Team USA, 2014). Early indications are that he will undergo surgery and be out until at least April. While a potential return to bolster a playoff run sounds enticing, Hayward is unlikely to be at full strength until next season.

“They know they can’t win the championship now,” acknowledged NBA analysts Charles Barkley and Shaquille O’Neal.

Fellow TNT colleague Kenny Smith took more of a long-term approach when looking at Boston’s newfound plight.

“The league is about growth and maturity,” the two-time NBA champion said. “And I really thought this was a baking process [with the Celtics], not a microwave. I didn’t think overnight this team was going to become a contender and beat the Cavaliers. I thought they’d have to bake, and a year from now - two years from now – [they could] be that team.”

If there’s a silver lining to Hayward’s injury, it will be found in the ‘growth and maturity’ of youngsters like Jayson Tatum, the Celtics’ first-round pick in this summer’s draft.

Tatum played 36 minutes in the 102-99 loss to Cleveland, recording 14 points, 10 rebounds and two assists on 5-of-11 shooting from the field. The rookie started the game due to the absence of Marcus Morris (right knee soreness), but will now assume a bigger role moving forward. Tatum was the primary benefactor of Hayward’s minutes Tuesday, taking the floor during crunch time and leaving an impression on a future Hall-of-Famer.

“He's way bigger than I thought," LeBron James said. “And way better than I imagined.”

Second-year pro-Jaylen Brown will also be called upon to produce in Hayward’s absence. After an impressive summer and preseason, the 6-foot-7 guard picked up where he left off, leading the team in scoring (25) and minutes played (40). Brown also added three steals, sharing defensive duties with Marcus Smart in trying to slow down James.

“Jaylen has put in a lot of time,” coach Brad Stevens said. “You can see that. He's just more comfortable than he was at this time last year.”

Fellow rookies Semi Ojeleye and Abdel Nader could also see some more exposure. A second-round pick in this year’s draft, Ojeleye saw nine minutes of action against the Cavs. Nader, 24, was named the D-League Rookie of the Year in April.

All options will be on the table for Boston, including applying for the Disabled Player Exception should Hayward be done for the season. The exception would free up $8.4 million in cap space, allowing the Celtics to sign a free agent before March 10. In the meantime, the grind of a grueling opening schedule will test Boston’s resolve.

The Celtics play host to the Milwaukee Bucks in Wednesday’s home opener at the Garden, leaving the team less than 24 hours to bounce back from a physically and emotionally draining loss to Cleveland. With the unlikely scenario of a strong contributor joining the team overnight, a preseason proclamation by Coach Stevens now sounds prescient.

"Our biggest challenge might be expediting the learning curve for the guys that are 19-to-21,” he said. “Because some of those guys have to play for us. We're in a position where a lot of the teams that have the guys that we've got are playing older guys off the bench. And we're not, right? So ultimately we've got to make sure that those guys have their learning curve expedited as quickly as possible."