New York ? The NBA players’ association plans to file a grievance against the Portland Trail Blazers, who have threatened litigation against any NBA club considering signing Darius Miles.

The former Trail Blazers forward is attempting a comeback — a potentially very expensive one for the Blazers — from major knee surgery.

If Miles plays in two more games this season, Portland, would be on the hook for $18 million — the amount remaining on Miles’ contract, which would count against Portland’s salary cap and force the team to pay luxury tax.

“We are shocked at the brazen attempt by the Portland Trail Blazers to try to prevent Darius Miles from continuing his NBA career,” players’ association director Billy Hunter said in a statement.

“Their attempt to intimidate the other 29 NBA teams by threatening frivolous litigation merely for signing this capable NBA veteran is a clear violation of the anti-collusion and other provisions of our Collective Bargaining Agreement. We will vigorously defend Darius’ rights.”

Hours before Miles cleared waivers Friday, Portland team president Larry Miller sent an e-mail to the other 29 NBA teams warning of legal action if a team were to take Miles simply to impact Portland’s salary cap adversely.

“Persons or entities involved in such conduct may be individually liable to the Portland Trail Blazers for tortuously interfering with the Portland Trail Blazers contract rights and perspective economic opportunities,” Miller’s e-mail reads, according to SI.com and Yahoo.com, which obtained it. “Please be aware that if a team engages in such conduct, the Portland Trail Blazers will take all necessary steps to safeguard its rights, including, without limitation, litigation.”

As a result of Miller’s e-mail, the issue was scheduled to be discussed Friday at a previously scheduled meeting between NBA and players’ union attorneys.

“Under league rules, teams are free to sign Darius Miles to a Uniform Player Contract if they wish to secure his services as a player, and any such contract would be approved by the NBA,” the league said in a memo sent to teams.