How bad is Marcus Smart’s injury? Even Danny Ainge doesn’t know

Marcus Smart cut his right hand Jan. 24, then hurt it again Sunday night.Michael Dwyer/Associated press

Danny Ainge spent Tuesday working at the team’s near-empty Waltham practice facility. There were no players there, mostly because of the snowstorm that pounded the region, but partly because few players are able to do much on the court right now.

“I’m healthy,” Ainge said by phone Tuesday night. “I might have to sign a 10-day [contract].”

The Celtics released a lengthy and star-studded injury report in advance of Wednesday’s game against the Wizards. They will be without Kyrie Irving (knee), Marcus Smart (thumb), Jaylen Brown (concussion), Daniel Theis (knee), and, of course, Gordon Hayward (ankle). The only slight sliver of hope came from the announcement that Al Horford, who missed Sunday’s game against the Pacers with an illness, has been upgraded to questionable.

“It’s just been unfortunate timing,” Ainge said. “I think they’re just fluky things that have happened, and it’s part of the game. You just have to deal with it.”

For the Celtics, the greatest immediate concern is the health of Smart. The fearless and sometimes reckless point guard injured his right thumb diving for a loose ball in the third quarter of the 99-97 loss to Indiana.

Smart has officially been diagnosed with a sprained thumb, but there is fear that tendon or ligament damage could require surgery that would sideline Smart for the rest of the season.

One league source said Smart’s outlook “doesn’t look good.” Ainge, meanwhile, acknowledged that surgery could be an option for the fourth-year guard, but said that Smart is hoping to take the next few days to see how the injury responds to treatment. He said Smart will also seek a second opinion from a hand specialist.

“Anything is possible now,” Ainge said. “I just don’t know yet.”

Smart, who will be a restricted free agent at season’s end, is prepared to play through pain, but if there is a chance he could further damage his hand then he would not risk it.

On Jan. 24, Smart needed 20 stitches in his right hand after punching a glass frame in his Los Angeles hotel room. He was sidelined for a month and said after he returned that the doctors who dislodged a large shard of glass said it had barely missed slicing tendons, an injury that would also have required season-ending surgery.

But Smart returned Feb. 23 and had played quite well since then. The career 36 percent shooter had made 43.2 percent of his attempts in eight games, and the Celtics had outscored opponents by 54 points while Smart was on the floor during that time.

Boston received other bad news Monday when it was determined that Theis will likely miss the rest of the season due to a torn meniscus. If Smart joins Theis on the sideline, it could be a crushing blow to the team’s hopes of reaching the NBA Finals.

Brown, meanwhile, remains in concussion protocol after taking a hard fall following a dunk in last Thursday’s game against the Timberwolves. Ainge said he was not sure how much progression Brown had made.

The news that Irving will miss Wednesday’s game comes as no surprise. The point guard has been dealing with left knee soreness this season, and it flared up recently. He missed the March 8 game against the Bulls and then exited the loss to the Pacers at halftime.

Irving is likely to miss several games, but Ainge said he thinks that Irving is “going to be fine” moving forward this season.

“Kyrie’s knee has bothered him, and we’re being very careful,” Ainge said. “What we don’t want to do is rush Kyrie back simply because we don’t have Marcus and Jaylen. We’ll do what’s best for Kyrie in spite of what’s happening to everybody else.”

If Horford is able to play against Washington, he could be joined in the starting lineup by Aron Baynes, Marcus Morris, Terry Rozier, and Jayson Tatum. That is a capable group, but Boston could run into issues when it has to go to its bench, with Greg Monroe, Shane Larkin, and Semi Ojeleye being the only obvious options. Rookies such as Abdel Nader, Guerschon Yabusele, and Kadeem Allen will likely get chances to play meaningful minutes in the coming days.

“I’ve seen many times where players that were not thought very highly of get an opportunity and make a name for themselves,” Ainge said. “So over these next couple weeks, there will be some guys that have those opportunities. We’ve seen players throughout the years that have responded, so this is a chance for some of our players to step up and see how much they can contribute to winning.”

The Wizards faced the Timberwolves in Washington on Tuesday night, but a team spokesman said in an e-mail that despite the weather, they were still scheduled to fly to Boston after the game. The Wizards will be without All-Star point guard John Wall, who is still recovering from January knee surgery.