While having both Al Horford and Je Crowder back in the near future will surely give a lift to the suddenly listing Celtics, and will shuffle players currently counted on to handle big roles back to more complementary ones, the team knows it can't wait until the squad is fully healthy to start playing better.

WALTHAM — The Celtics may be one step closer to getting their $113-million man back.

When Al Horford does return from the NBA’s concussion protocol, he will be rejoining a team that is in the midst of some serious soul searching following a second straight blowout loss Wednesday night in Washington D.C.

Celtics coach Brad Stevens struck a positive tone for the second straight day on Horford following Thursday’s light workout, saying that the four-time All-Star and prized free-agent acquisition was cleared to return to the practice floor after a week in the protocol. The coach cautioned, however, that the team did not do any contact in practice and that it is still doubtful Horford will be cleared in time for Friday night’s game against the New York Knicks at TD Garden.

Stevens added that he does not expect to have forward Jae Crowder back from his left ankle sprain until next Wednesday’s game against the Dallas Mavericks “in a best-case scenario.”

While having both back will surely give a lift to the suddenly listing squad, and will shuffle players currently counted on to handle big roles back to more complementary ones, the players know they can’t wait until the squad is fully healthy to start playing better.

“All the things we’re getting beat at are not because certain guys are out,” Celtics point guard Isaiah Thomas said. “It’s because we’re not playing with our heart. We’re not giving it our all for whatever reason.”

Stevens said he felt the effort was there in Wednesday’s loss, but the execution was lacking — especially on the glass where Washington grabbed 19 offensive rebounds, and outrebounded the Celtics 54-31, in a 118-93 final.

“Guys are all a step slow,” Thomas said. “Everything we do on offense and defense is, like, hesitant. We’ve never been that way. That goes with the 50/50 balls. That goes with being the hardest-playing team.

“We’re not getting those (rebounds) because we’re not playing hard — or four guys are playing hard and one guy is not. So as a collective group we’ve got to do a better job knowing that, even though we are small, that gives us no excuse. The bigs have to hold off their bigs and the guards need to help the bigs rebound.”

While Stevens said he would consider lineup changes for Friday night, he noted he needs more from whoever is on the floor with Crowder and Horford out regardless of who starts and who comes off the bench.

“Guys who haven’t done this yet are playing,” the coach said of rookie Jaylen Brown and second-year players Jordan Mickey and Terry Rozier. “There’s some things you learn over time. The best thing that we all can do is move on to the next play and do our jobs the best we can. When the other team is drubbing you, the best of the best can move past it, but everybody gets affected a play or two.”

Thomas pointed to not having Evan Turner — who signed for four years and $72 million with the Portland Trailblazers as a free agent this summer — as well as the absence of Crowder as a vulnerability at the wing position during the three-game slide.

“Now we’ve got a rookie in his place,” Thomas said of Brown. “Things are coming fast for him and he’s got to think on the fly as well, and at the same time play at a high level.”

Brown has scored just seven points in the two games since his 19-point breakout performance against LeBron James and the Cleveland Cavaliers last Thursday, while Rozier was a minus-14 in going scoreless in 14 minutes Wednesday night. Mickey was a minus-9 in less than eight minutes on the floor in Washington.

Thomas said, however, that the tone-setting has to come from the veterans who have been here and done it the past two seasons.

“It starts with the starters,” he said. “We’ve got to play better. Then we’re putting our second unit in a hole, and if they don’t come out aggressive with energy, then we’re in an even bigger hole.”

“We need to be the Celtic team I’ve been a part of the last year-and-a-half. That’s being the hardest-working team, being scrappy, getting all the 50/50 balls, and all that.”

Scott Souza can be reached at ssouza@wickedlocal.com. Follow him on Twitter @Scott_Souza.