John Wall will remain on the sideline for most, if not all, of next season. (Jonathan Newton/The Washington Post)

Washington Wizards all-star guard John Wall ruptured his left Achilles' tendon “after slipping and falling in his home” and is expected to be out at least 12 months from the time of his to-be-scheduled surgery, the team announced Tuesday. He could sit most, if not all, of the 2019-20 season.

Before this latest setback, the 28-year-old guard was already expected to miss six to eight months after undergoing a procedure to remove bone spurs from his left heel Jan. 8. One of the reasons Wall opted to undergo that season-ending surgery was to avoid a more serious issue, such as an Achilles' tear. But Wall stumbled inside his home on Jan. 29, which led to the rupture, according to Wiemi Douoguih, the Wizards' director of medical services.

An initial checkup after the fall showed nothing abnormal, but Douoguih said he discovered the extent of the damage Monday while performing a surgery on Wall to address an infection of the original surgical wound.

“We tried to put him on antibiotics, [but the surgical site infection] wasn’t getting better. So we just went to explore it and incidentally found that he had a rupture at the time of the surgery,” Douoguih said. “It wasn’t completely ruptured in that there were a few strands still attached and that’s likely what threw off our examination but there’s no question that functionally the tendon was torn at the time of that surgery."

Wall, a five-time all-star and the 2010 No. 1 overall draft pick, averaged 20.7 points, 8.7 assists and 3.6 rebounds in 32 games for the Wizards this season. While the franchise is “disappointed” for its star guard, the team expects Wall to play at some point in the 2019-20 season, according to a person connected to the Wizards who spoke on the condition of anonymity. That is far from a guarantee, however: Recovery could range from 11 to 15 months, Douoguih said, and if Wall’s timeline is closer to 15 months, then he would not return to full basketball activity until May 2020. At that point, the Wizards will either be in the playoffs or at home awaiting a lottery pick.

The latest development with Wall may have little impact on the team’s plans for this season, according to a person with knowledge of the situation. Last week, majority owner Ted Leonsis announced in a radio interview that the team will not trade Wall, Bradley Beal or Otto Porter Jr., three players who are paid the maximum amount available based on their experience in the league. Wall has a four-year, $169.3 million “supermax” extension kicking in next season.

Following Tuesday’s Wall injury news, the team remains reluctant to part with Beal and, to a lesser degree, Porter. But the Wizards will still engage in talks with other teams in advance of Thursday’s NBA trade deadline in the hopes of improving the roster this season and long term. The Wizards (22-31) are in 10th place in the Eastern Conference and have gone 9-9 since Wall left the lineup.

Wall has been the face of Washington basketball since 2010 when the Wizards rolled out the red carpet (literally) for the skinny, 19-year-old would-be savior. He ushered the franchise past the Gilbert Arenas-Javaris Crittenton gun fiasco and lifted the team to Game 7 of the 2017 Eastern Conference semifinals. He also has led in the community and gave a $400,000 assist to Bright Beginnings, a learning center for families and children experiencing homelessness.

His star power on the court and generosity off it earned Wall the city’s admiration, but his last several years in Washington have also introduced a worrisome injury trend. This will be Wall’s fifth major surgery since the spring of 2016.

Wall has remained optimistic and expressed some relief that the injury occurred while he was already expected to miss significant time, according to a person close to the point guard. Wall was described as taking the news in stride because he has experienced greater setbacks in life, including losing his father when he was 9 years old.

Golden State Warriors center and Wall’s longtime friend, DeMarcus Cousins, who recently returned from an 11-month recovery from his own ruptured Achilles', expressed confidence in Wall’s bounceback capabilities.

“I talked to him this morning. It sucks. It’s unfortunate,” Cousins, who played the 2009-10 college season with Wall at Kentucky, told reporters. “But me knowing John as well as I do, I know he’ll overcome this. There’s no doubt on my mind about that. He’s overcome a lot of hard obstacles in his life. Just add this to the list.”

Not long ago, Wall was soaring.

It was a Friday night in July 2017 when Wall, shirtless and recording himself in front of a mahogany wardrobe, shared news on social media that he had agreed to a contract extension with the Wizards. At the time, the deal marked a celebratory occasion for a fan base that had persevered through years of losing, lottery picks and irrelevance. When so many stars in the NBA were bolting their homegrown teams, the Wizards' franchise player had chosen to stick with Washington.

“I know some people probably went out and had some drinks after,” Wall said, smiling at his official news conference to recognize the contract.

Those toasts have since ended. And the fans may need a drink, or three, to drown their sorrows over the bleak outlook for the Wizards, facing a bloated payroll, and Wall, who will undergo surgery as early as next week that will be performed by Robert Anderson, the same doctor who handled the procedure on his left heel in Green Bay, Wis., in January.

Wall now faces the toughest challenge in his NBA career: attempting to recover his speed, strength and athleticism following one of the most difficult injuries for a basketball player.

“You know, there’s no way to tell,” Douoguih said. “I think our focus right now is on performing an excellent surgery, getting John’s tendon reattached and then going through the rehab program. I don’t think we can say. . . . We don’t have a whole lot of data on elite NBA point guards with tendon ruptures. John is an unusual specimen because of his talent, his abilities and the demands placed on his body, so we’ll just have to wait and see.”

Scott Allen contributed to this report.

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