BALTIMORE (AP) _ When Eternal Prince rockets out of the starting gate at Saturday's Preakness with Chief's Crown right behind, they may have company - Skip Trial, who won last week's Preakness Prep wire-to-wire.

With Kentucky Derby winner Spend a Buck bypassing the second leg of the Triple Crown, his frontrunning role in the Preakness figures to fall to Eternal Prince, who got a slow start in the Derby and wound up 12th. He worked a brisk six furlongs Sunday in 1:11 1-5 under new rider Chris McCarron, who flew in from California just for the workout.

But Skip Trial, who went 1 1-16 miles in 1:42 2-5 in last Saturday's Prep, may contest the early lead and so may Chief's Crown, who wound up third in the Derby as the favorite.

''Skip Trial runs better when he has something to run at, but he went to the front so easy in the race there was nothing we could do,'' said the colt's trainer, Sonny Hine. ''When you consider how easily he won this race, his performance was awesome.''

Meanwhile, a 12th horse, T.W. Reiber's Sport Jet, was entered Tuesday for Saturday's race. Sport Jet will have to pay a $20,000 supplemental fee to enter, making the total value of the Preakness a record $553,000 if all projected starters run.

The strategy of the race may depend on the draw for post positions, particularly for Skip Trial and Chief's Crown.

Pimlico usually favors speed horses, so it figures that the contenders will be close to the front in the 1 3-16 mile Preakness, 110 yards shorter than the Derby.

''Eternal Prince has to try for the lead,'' said Hine. ''And after the way Spend a Buck won the Derby when Chief's Crown did not go after him early, I feel they will have Chief's Crown closer to the pace this time. My horse will be right behind them and they're going to have to keep running at the end or Skip Trial is going to beat them.''