Nelson, the team's leading scorer and rebounder last season, had been suspended indefinitely for conduct issues, including sulking, not participating in timeout huddles and being argumentative with coaches and teammates.
He sat out Tuesday's loss to Middle Tennessee State, but met with Howland Wednesday afternoon to discuss his issues and will travel with the team to Hawaii next week for the Maui Invitational.
"Reeves understands that his reinstatement is contingent on his ability to continually meet the high standards we have established for all UCLA men's basketball players," Howland said in a statement. "He expressed to me in our meeting earlier today that he desires to be a better person and better teammate going forward, and, given that, I feel as though I should give him that opportunity."
Nelson scored 13 points and eight rebounds in a season-opening loss to Loyola Marymount last Friday, but appeared flustered and aloof during the game. He had a verbal altercation with Howland the next day at film sessions and did not show up for practice the following day.
After a phone conversation with Howland and his parents, Howland suspended Nelson indefinitely pending a face-to-face meeting. That meeting took place on Wednesday.
"I acknowledge there are corrections that need to be made and I'm grateful to Coach Howland to have this opportunity to improve and work on being a positive force for our team," Nelson said in a statement. "I appreciate the support of my teammates and will be there for them as we move forward."
Peter Yoon covers UCLA for ESPNLosAngeles.com.