The Philadelphia 76ers announced their 11-man roster for the Princeton Summer League, which begins Monday and includes teams from the New York Nets, New York Knicks and Washington Bullets. The Bullets will announce their roster today.

The 76ers' roster for the week-long league at Jadwin Gym includes rookie forwards Terry Catledge -- the club's No. 1 draft pick -- Greg Stokes, Voise Winters, Derrick Gervin and Daryl Lloyd; forward Leroy Combs, centers Jeff Cross and Mike Davis and guard Keith Walker, all free agents; and veteran guards Sedale Threatt and Leon Wood. FOOTBALL

U.S. Football League teams yesterday protected 330 players by placing them on offseason rosters designed to retain players during the league's 18-month layoff. Each franchise, except those facing the prospect of a merger, placed a minimum of 35 players on its protection list.

The Denver Gold, Los Angeles Express and Oakland Invaders, all possible merger candidates, protected 15 players each. The New Jersey Generals and the Houston Gamblers, who merged this past week, protected a combined total of 37 players. The San Antonio Gunslingers and Portland Breakers, clubs that waived their entire rosters because of delinquent salary payments, and Chicago, which did not stock a roster for its 1986 season, were not part of the proceedings.

Any player not protected is a free agent and can sign with the NFL.

Some of the more prominent players protected include quarterbacks Doug Flutie and Jim Kelly of the New Jersey-Houston team, running back Kelvin Bryant of Baltimore and wide receiver Anthony Carter of Oakland.