The Celtics trimmed off the bottom portion of their training camp roster Thursday, cutting three players who likely are bound for the G League.

Boston waived guards Ron Harper Jr. and Jay Scrubb and forward Hason Ward, all of whom were with the team on Exhibit 10 tryout contracts.

Of the three, only Harper saw preseason action for the Celtics, appearing in three of Boston’s five exhibition games and logging a team-low 12 minutes. The 24-year-old NBA legacy also played for the Celtics’ Las Vegas Summer League team.

Scrubb, who tore his ACL during a Celtics practice last October, re-signed with the team earlier this month but did not play in the preseason. Ward, an undrafted rookie big man who attended high school at Springfield Central in Western Massachusetts, signed with Boston on Wednesday.

Harper, Scrubb and Ward are prime candidates to join the Celtics’ G League squad in Maine.

The fate of Boston’s most notable E-10 player, Lonnie Walker IV, remained unclear as of Thursday evening.

Walker, a seventh-year veteran with 322 games of NBA experience, signed a tryout deal with the Celtics after failing to land a guaranteed contract in free agency. The 25-year-old wing scorer played well in Boston’s two tuneup games at TD Garden — nine points, seven assists, four rebounds, two steals in the first; 20 points on 8-of-15 shooting in the second — but did not leave the bench in Tuesday night’s preseason finale in Toronto.

The Celtics have one open spot on their 15-man roster, but president of basketball operations Brad Stevens could choose to leave it vacant for flexibility and financial purposes. Because the Celtics are well over the NBA’s luxury tax threshold, permanently signing Walker, even for the veteran minimum, would cost close to $10 million in tax penalties.

Though Walker has not played in the G League since his rookie year in 2018-19, he said he would be “perfectly fine” with being assigned to Boston’s farm club.

“I’ve got to earn (my spot),” Walker said early in training camp. “Obviously, there’s a lot of different aspects that might carry onto it, but being on an E-10, it’s not guaranteed. I’m not coming here with the mindset of, ‘OK, I’m on an E-10 and afterwards, I’m going to get the guaranteed contract.’ It’s like, I’ve got to work my tail off. I really have to, each and every day, put it all out on the court. First one in the gym, hopefully the last one out, come back later on, shoot and just be mentally and physically prepared for the outcome.”

Walker appeared in 58 games off the bench for the Brooklyn Nets last season, averaging a career-high 20.1 points per 36 minutes.

Boston’s regular-season roster must be set by 5 p.m. ET on Monday. The Celtics open the season one day later against the New York Knicks at TD Garden.