Plagued by a slow start to the season, White has begun to resemble the efficient scorer of his past seasons with the Celtics. In his past six games, White is shooting 38 for 77 (49.3 percent) and 19 for 47 (40.4) from the 3-point line. With Brown nursing an illness as the Celtics prepare for their Friday 7 p.m. showdown against the Lakers at TD Garden, White became the primary scorer and flourished with the added responsibility.

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White admitted his waning confidence had been a persistent concern during his skid.

“Yeah, it’s something I’ve dealt with my whole life,” White said of keeping a positive mind-set.staying positive. “I’d like to say I’ve gotten a lot better at that. So who knows how bad I was when I was a kid. But, yeah, it’s definitely a challenge. High expectations for yourself, and you want to increase those, but there’s a constant reassurance that’s just in basketball, there’s ups and downs, and you got to kind of work your way through that.”

A game against the tanking Wizards provided ample opportunity for the Celtics to pile up offensive stats. They shot nearly 55 percent and were 20 for 47 from the 3-point line, putting the game away with a 43-point third quarter after leading just 66-59 at halftime.

Jordan Walsh soared for the Celtics with a career-high 22 points, including 15 in the first half of a 146-101 rout of the Wizards on Thursday night in Washington, D.C.John McDonnell/Associated Press

Walsh, the third-year forward, set a career high with 15 first-half points and finished with 22 points on 8-for-8 shooting. He added 7 rebounds and 3 assists as his contributions to the club continue to be one of the season’s biggest surprises.

Walsh wowed the large turnout of Celtics fans in D.C. with two hammer dunks in the third quarter as Boston scored at will. The Wizards appeared to lose interest as only two players — CJ McCollum (team-high 22 points) and Justin Champagnie (9 points on 3-for-6 shooting) — recorded more than one basket in the second half.

Meanwhile, Celtics coach Joe Mazzulla was able to rest three of his starters for the entire fourth quarter as they used an 11-2 run to end the third for a 109-86 lead. Boston is 8-2 in its last 10 games and have navigated a difficult schedule stretch against multiple Eastern Conference contenders.

With home losses to Utah and Brooklyn in the past few weeks, this was considered a potential trap game with the Lakers looming.

“I thought we played with a good level of energy throughout the entire game,” Mazzulla said. “I don’t know if it was as much about guys playing different roles, it was guys making sure they do their jobs and they play their absolute best and stick to the game plan and play with a level of physicality. Everybody did that.”

With Jaylen Brown out of the lineup, Celtics coach Joe Mazzulla lauded Derrick White’s impact in Thursday night’s 146-101 victory over the host Wizards. “He does a really good job of just knowing when to take over and when to facilitate and he can be a steadying force and he can go on a run by himself,” Mazzulla said.John McDonnell/Associated Press

Mazzulla has offered grace for White during his struggles because of his defensive and playmaking contributions. He scored 12 points in the first and third quarters as the Celtics played perhaps their best offensive game of the season — all without Brown, their leading scorer.

“He has a lot of responsibility and he’s carried us for a while as far as leading the team in steals, leading the team in blocks, doing everything defensively,” Mazzulla said of White. “He does a really good job of just knowing when to take over and when to facilitate and he can be a steadying force and he can go on a run by himself. He’s got that ‘it’ factor at times. I thought in the middle of the second quarter is when he went on his run. I felt like when we put the ball in his hands, we go great things. He’s playing well offensively for us.”

Washington has perennially served as a comfortable road venue for the Celtics due to the strong turnout of fans and Thursday night was no different. Jayson Tatum was applauded as he walked through the tunnel onto the floor early in the first quarter while White was given a large ovation by Celtics fans who stayed for the entire game as he walked off the floor.

The fact White is beginning to return to previous form is an encouraging sign for the streaking Celtics, who have climbed up to fifth in the Eastern Conference standings. They now have two games against the Lakers at home Friday and vs. Raptors in Toronto on Sunday remaining in perhaps their most difficult stretch — four games in six days — of the season. stretch of the season.

“I was definitely a lot more on the ball this game and tried to create and get us into the offense,” White said of his season-high performance. “Obviously with JB out, it’s a little bit different. Every game is a different challenge and I look forward to it.”

Gary Washburn is a Globe columnist. He can be reached at gary.washburn@globe.com. Follow him @GwashburnGlobe.