Seattle Slew, which was a 2-to-1 second choice when he upset Affirmed a fortnight ago in the $300,000 Marlboro Cup Handicap, will be an overwhelming favorite to lead five opponents from wire to wire in today's $150,000 Woodward Stakes at Belmont Park.

The Woodward might have become the dream race of 1978 with a rematch of Triple Crown champions Seattle Slew and Affirmed, topped off by the first appearance in New York this season of the California-based Excellers, a stretch runner of high quality. It would have been a three-way showdown for Horse of the Year.

But Harbor View Farm's Affirmed will be napping in his stall at Belmont when the Woodward field goes into the gate of 5:43 p.m. (WDVM-TV-9). The 3-year-old Affirmed is awaiting the $300,000 Jockey Club Gold Cup two weeks from today.

"That $100,000 make a lot of difference," said Barrera, who should knowing money-making trainer in North America for the third straight year. When someone suggested Affirmed was dodging Seattle Slew, owner Louis Wolfson retorted, "If Seattle Slew wants to be Horse of the Year, he can run againt us in the Gold Cup at a mile and a half."

Seattle Slew, however, is likely to pass up the Gold Cup and go for the sprint championship in the Vosburgh Handicap Oct. 21 and the grass title in the Washington, D.C. International Nov. 11 at Laurel. If Slew beats Nelson Bunker Hunt's Exceller in the Woodward, he could wind up with three Eclipse Awards for divisional titles, but still not be Horse of the Year.

"If Affirmed still wins Horse of the Year," said co-owner Mickey Taylor, "it won't kill us. We know Slew's a better colt and after the Marlboro; the whole world knows it."

Great Contractor, Wise Philip, It's Freezing and Appasionato will be rank outsiders in the Woodward, with Exceller the main contender.

Charlie Whittingham, trainer of Exceller, hoped Affirmed would be in the lineup to keep Angel Cordero-Jr., from setting a slow pace with Seattle Slew. With Affirmed out, Whittingham conceded, "If it was a mile and a half, I wouldn't worry. But I don't know if we can catch Slew going a mile and a quarter."

Trying to put more zip into Exceller, jockey Bill Shoemaker worked the 5-year-old a half-mile in a crisp :46, Thursday. "We'll just have to do the best we can under the circumstances," Shoemaker said. The 47-year-old jockey will catch a 7:30 p.m. plane to Paris after the Woodward in order to ride Hunt's Trillion in tomorrow's rich Arc de Triomphe.