In another bizarre move from pro basketball’s most bizarre franchise, the Los Angeles Clippers announced Monday that general manager Neil Olshey — whom they had said three days ago had agreed to terms to remain with the team — was instead leaving, with sources confirming that Olshey would be named the Trail Blazers’ new GM. A news conference is expected in Portland Tuesday.

Olshey, who engineered the trade that brought All-Star Chris Paul to the Clippers in a franchise-altering deal in December, had been working all season without a contract, with owner Donald Sterling unwilling to sign him to a long-term deal.

On Friday, the Clippers had announced Olshey had agreed to terms on a new deal, with a conference call set up for Monday afternoon. But one side clearly didn’t think a deal was done.

“Circumstances have obviously undergone some movement since our announcement Friday. In light of that, we want to wish Neil well and acknowledge his contributions during the time he spent with the Clippers,” team president Andy Roeser said in a statement released by the team Monday afternoon.

Olshey had been the Clippers’ GM for two years, replacing Mike Dunleavy in 2010, and his acquisition of players like Paul and free agent forward Caron Butler dramatically re-shaped the team’s roster. But he interviewed with Blazers owner Paul Allen a couple of weeks ago in Europe, and was believed to be Allen’s choice for the job.

In Portland, he will replace interim GM Chad Buchanan, who had been the Blazers’ acting GM since the team fired Rich Cho last summer. The Blazers had interviewed several candidates for the job, including TNT analyst Steve Kerr and former New Orleans Hornets GM Jeff Bower. Portland may also be looking for a new head coach to replace interim head coach Kaleb Canales, who replaced the fired Nate McMillan in February.

Olshey opted for Portland, according to a source, because the Blazers — while not being an easy place to work either, having fired several executives in the last three years, including Cho, his predecessor, Kevin Pritchard, and Pritchard’s assistant, Tom Penn — nonetheless have the resources available to be involved in any transaction. With Allen’s largesse, the Blazers are always potential players in any trade, free-agent signing or Draft day deals. The Blazers currently have the sixth and 11th picks overall in this month’s Draft.

In Los Angeles, Olshey only had a handful of people working with him in the basketball operations staff — “he was basically MacGuyver down there, “ a source said — and had difficulty getting decisions made quickly. Nonetheless, he had enough clout to dramatically, and historically, remake the Clippers’ roster in a frantic two-week frame in December.

First, after the NBA, which owned the Hornets at the time, controversially vetoed a three-team trade that would have sent Paul to the Lakers, Olshey was able to leverage the Clippers into position to make a deal with New Orleans to acquire Paul in exchange for guard Eric Gordon, forward Al-Farouq Aminu, center Chris Kaman and a 2010 first-round pick.

Then, the Clippers signed Butler to a three-year, $24 million deal. They followed that by convincing guard Chauncey Billups to report to the team after they claimed him off waivers from the Knicks. Finally, the Clippers matched a four-year, $43 million offer sheet that restricted free agent center DeAndre Jordan received from Golden State.

During the season, Olshey added veteran big man Kenyon Martin, who’d been playing in China during the lockout, signed free agent Reggie Evans and acquired guard Nick Young from Washington as part of a three-team trade.

With the team’s new core surrounding third-year star Blake Griffin, the Clippers dealt with expectations they had never dealt with before. For the first time, there were serious questions asked about which Los Angeles basketball team was better. In the end, both the Clippers and Lakers reached the second round of the playoffs, and while that was a disappointment for the Lakers, it marked only the second time in 35 years that the Clippers had gotten that far in the postseason.

A search for a replacement for Olshey is already underway, headed up by Roeser. In the interim, all responsibilities pertaining to the team’s basketball operations will be absorbed by Roeser, head coach Vinny Del Negro, and Clippers’ Director of Player Personnel Gary Sacks.