Trainer Johnny Campo says that it "wouldn't surprise him" if his horse, Media, won the Kentucky Derby this Saturday.

That's significant, because it reflects an interesting mood in Louisville this week. Nobody disputes the fact that John L. Greer's Foolish Pleasure is the horse to best this weekend, but by the same token no one is taking that victory for granted. In fact, the expectation is that Saturday's classic run at Churchill Downs will be just that: a spectacular horse race.

Tension is now the password in Barn 42, as Greer and trainer Leroy Jolley await the biggest test of Foolish Pleasure's racing career. While the colt has captured headline after headline on route to ten victories in eleven career starts, the rapid development of other powerful contenders has drastically changed the complexion of the 101st Derby.

With little more than 48 hours left until post time, Campo's Media is just one of at least five contenders who have a legitimate chance to run down the currently undisputed king of the three-year olds. Which is somewhat surprising, considering that a few short months ago Foolish Pleasure was the accepted heir to Secretariat's throne, an odds-on choice to become the second Triple Crown winner in 27 years.

Recent weeks, however, have shown that trainer Jolley is in charge of just one of many excellent three-year olds, and that Foolish Pleasure's road to glory will be a tough one to navigate.

The first clue to a return to normalcy came on March 29, when an unbeaten Foolish Pleasure came up empty in the stretch run of the Florida Derby, finishing third behind John Galbreath's terrific twosome of Prince Thou Art and Sylvan Place.

The next chapter was written in the Wood Memorial at Aqueduct eleven days ago, when a speedy pace-setter named Bombay. Duck gave the champion all he wanted down the long stretch run of a grueling mile and one-eighth test.

Foolish Pleasure was more than normal in that one, tying Bold Ruler's longstanding record time of 1:48 4/5 for the nine furlongs. Just as important, however, was the Duck's vault into stardom, as he was just a head behind when the two went under the finish wire.

To top it oft, Johnny Campo will tell you that Media should have won the race.

The Wood Memorial was only Media's fourth lifetime start, and the colt matched Greer's champion almost stride for stride throughout, finishing just one length behind. Campo complained after the race that his jock, Jean Cruget, had moved the horse a little too soon, and that he should have waited until the stretch.

Whether that criticism holds water is debatable, but the fact remains that Media was one tick off a track record an one length behind Foolish Pleasure at the end of the fourth race of his life.

Around New York circles it is generally accepted that if Media and Bombay Duck could give Foolish Pleasure a run for his money, then Miss Cynthia Phipps's Singh could have beaten them all. Singh was far and away the best in the New York circuit, but a pulled ligament put him out of action for the Wood and the Derby. As it stands, Singh could well be a dramatic spoiler in the third leg of the Triple Crown, the Belmont Stakes. It all depends on how he comes back from the dangerous injury.

While Media and Bombay Duck were throwing their weight around in New York, the Louisiana Derby of March 22 was taken by a lightly regarded Master Derby. For horse racing myopics who are chauvinist about Eastern racing, that feat came into focus last week, when Master Derby trudged his way through the slop to win the Blue Grass Stakes, his fifth consecutive victory and an important Derby prep.

Prince Thou Art was in that one, and so was Sylvan Place, and while they both raced unimpressively it's only fair to chalk up the track condition as a possible factor. Master Derby takes after his father (Dust Commander, 1970 Derby winner on an off track) in his love for the mud. But wet or dry, he is sharp and ready for this weekend's action.

Master Derby's mud-running heroics last week also eclipsed the valiant efforts of a horse named Harvard Man, who left the gate in the Blue Grass as a 35-1 long shot and finished eighth in the field of nine. Harvard Man, who finished second to Foolish Pleasure in the Champagne Stakes last year, has been one of the biggest disappointments of this racing season, to say the least.