A judge is playing hardball with the Columbia University students rounded up in an alleged dorm- and fraternity-based drug ring last year.

Manhattan Supreme Court Justice Michael Sonberg yesterday barred two of them — Gates Millennium Scholar José Perez and former senior engineering student Michael Wymbs — from applying for a program that would have kept them from having felony records.

Perez, accused of using his insurance to purchase, then resell, prescription Adderall pills, and Wymbs, accused of selling LSD, had asked the judge to recommend them for the Judicial Diversion program. A third suspect was allowed to apply.