BASKETBALL Philadelphia 76ers -- Declared F Cliff Robinson (19.1 ppg), with lower back strain and muscle spasms, will miss Sunday's and Monday's games against the Washington Bullets at Capital Centre. Milwaukee Bucks -- Activated F Larry Krystkowiak (idled Jan. 12 with tendinitis in foot). C/F Dave Hoppen decided not to re-sign as 10-day contract expired.

BASEBALL Minnesota Twins -- Signed SS Greg Gagne to a one-year, $440,000 contract under which Gagne, who had filed for arbitration, can earn $25,000 more in incentives.

FOOTBALL New York Giants -- Signed an agreement with Fairleigh Dickinson University to use the Madison, N.J., campus for preseason training; previously the NFL club used Pace University, Pleasantville, N.Y., as training base.

HOCKEY Minnesota North Stars -- Traded C Keith Acton, 29 (eight goals, 11 assists this season) for D Moe Mantha, 27 (2 G, 14 A) of the Edmonton Oilers. C Dennis Maruk, the former Washington Capital, was supended three games by the NHL for high-sticking Toronto's Wendel Clark on Jan. 13. Philadelphia Flyers -- Traded LW/C Lindsay Carson, 27 (2 G, 7 A this season) to Hartford Whalers for LW Paul Lawless, 23 (4 G, 5 A).

SKI JUMPING World Cup -- Pavel Ploc of Czechoslovakia won his fourth event of the Cup season in Gstaad, Switzerland; Finland's Olympic hope, Matti Nykaenen, placed fifth.

COLLEGES Wake Forest -- Afforded football coach Bill Dooley an extension of his five-year contract; announced plans to upgrade football and other athletic facilities. Washington -- Dropped the mandatory aspect of its drug testing program for student-athletes, challenged in court by runner Betsy O'Halloran. Lafayette -- Basketball coach Butch van Breda Kolff, who left with chest pains before the end of Thursday night's victory over Drexel, in satisfactory condition in a hospital. Diagnosis: arrhythmia (irregular heartbeat). Pittsburgh -- Academically ineligible basketball G Mike Goodson said he will transfer to Fordham.

JURISPRUDENCE Opelika, Ala. -- Former Atlanta sports agent Jim Abernethy pleaded not guilty to three misdemeanor counts stemming from payments he made to Auburn football star Kevin Porter during the 1987 season. Trial is scheduled Feb. 29.