Nike founder Phil Knight and Los Angeles Dodgers part-owner Alan Smolinisky have delivered a written offer of more than $2 billion to purchase the Portland Trail Blazers and plan to remain aggressive in acquiring the team, sources told ESPN on Thursday.

Knight and Smolinisky have engaged in discussions with the Paul Allen Trust overseeing the franchise, but a Trail Blazers spokesperson issued a statement Thursday saying simply: "An offer was made by Phil Knight. The team remains not for sale."

Forbes listed the Blazers value at $2.05 billion in 2021, and it's believed that the Knight-Smolinisky bid has landed in that range. Knight has a long, close relationship with NBA commissioner Adam Silver, and both Knight and Smolinisky have had conversations with the league office on a possible bid, sources told ESPN.

Nevertheless, several groups interested in prying away the Blazers in a sale have made their interest known to the Paul Allen Trust and league office, sources said. Perhaps, though, no prospective group has the cache and star power in the Pacific Northwest as a Phil Knight-led bid.

Knight's deep ties to the region -- with Nike and his support of his alma mater, the University of Oregon -- reflect the prospective ownership group's desire to keep the team in Portland for the long term, sources said.

Allen's sister, Jody, has been managing the trust since her brother's death in October 2018. The belief has long been that sales of the Blazers and the NFL's Seattle Seahawks are part of an eventual plan for the trust.

NBA commissioner Adam Silver said at his annual press conference ahead of Game 1 of the NBA Finals Thursday night that the team will have to be sold, per the terms of the trust, but that he did not know when a sale would take place.

"I don't know all the specifics of Paul Allen's trust. What I understand is that Jody Allen, who is Paul Allen's sister, is the trustee of the estate and that at some point, the team will be sold," Silver said. "I don't have any sense of the precise timing. I read that same statement today in which she or someone on behalf of the estate said the team is not currently for sale. But at some point it will be for sale. This is a hugely complex estate, and although it's been several years, these things take time.

"It will work its way out, but I know Jody and her advisors are very focused on it. As to the timing, that is something her brother left in her hands."

Silver added that it is both his and the NBA's preference that the team remain in Portland.

Portland is considered one of the league's smaller media markets, but the team has a long history of rabid fan support and regular-season and playoff success. Forbes' valuation has the Blazers as the 13th most valuable franchise in the NBA.

Another small-market team, the Minnesota Timberwolves, recently sold for a valuation of $1.6 billion.

Knight, 84, is considered one of the 25 richest people in the United States, worth north of $50 billion. He was born in Portland, graduated from Oregon and stepped down as chairman and CEO of Nike in 2016 after 52 years running the company.

Smolinisky joined the Dodgers as a limited partner in 2019. He has been successful in commercial real estate and investing.

The Blazers are undergoing a franchise makeover on the basketball side that includes new general manager Joe Cronin and Chauncey Billups entering his second season as head coach.

ESPN's Tim Bontemps contributed to this report.