Irving has requested a trade, indicating he wanted to join a team where he could emerge from James's shadow.
"These things are fluid," Gilbert said of Irving's situation at a press conference at the team's Ohio training facility, Altman's first since he was confirmed as the team's new general manager on Monday.
Numerous US media outlets have reported that Irving has requested a trade, indicating he wanted to join a team where he could emerge from James's shadow and become the focal point of the offense.
"We think that Kyrie Irving is one of the best guards in the NBA," Gilbert said. "He was part of a championship, three years straight to the Finals and we value his talent significantly."
Irving played the last three NBA Finals alongside James with Cleveland, winning the title in 2016 and falling to the Golden State Warriors in 2015 and this year.
He has two seasons left on his contract and a player option for 2019.
Whatever his reason for wanting to leave, Altman -- who served as assistant GM under Dan Gilbert, who departed in June -- said reports of friction between James and Irving were "overblown".
"I think the people who are in this building every day haven't seen any of that animosity," Altman said. "This is, along with Kevin Love, this is a group that got us to three straight Finals and won an NBA championship together. They play great together on the floor and a lot of that I do think is overblown."