Their NASCAR team owners -- Chip Ganassi for the No. 40 Dodge Franchitti drives and Roger Penske for the No. 77 Dodge Hornish drives -- both said the Indy 500 is not part of the plan this season.
The two Cup rookies will concentrate on the Coca-Cola 600 Cup race that day (May 25) at Lowe's Motor Speedway in Concord, N.C.
Penske, who is traveling in Europe this week, called Rusty Wallace on Tuesday from England to tell him Hornish would not race at Indy this year.
"Roger said he's very happy with what Sam has done this year and they don't want to do anything to disrupt that," said Wallace, who drove for Penske before retiring after the 2005 season. "Roger entered a third car at Indy, but that's only to use if they wreck one of the others."
Penske wanted to end the speculation that David Stremme would replace Hornish in the Coca-Cola 600 so Hornish could race at Indy. Hornish is a three-time IndyCar Series champion and the 2006 Indy 500 winner. He ranks 33rd in the Cup standings this season after eight races.
The rumors about Hornish racing at Indy started when Stremme was hired this week by Penske Racing as a test driver for the Cup operation. Penske fields three Cup cars -- the No. 2 Dodge driven by Kurt Busch, the No. 12 Charger driven by Ryan Newman and the new No. 77 team with Hornish.
Stremme also drives for Rusty Wallace's Nationwide Series team.
"Roger said he hired Stremme just to help them get more input and hopefully improve all three Cup teams," Wallace said.
The speculation about Hornish also brought rumors about Franchitti possibly returning to the Indy 500 next month to defend his victory from last season.
But Ganassi made his feelings clear: "No way we're doing that," Ganassi said.
Ganassi also said that Franchitti is totally committed to his move to NASCAR.
Franchitti, who won his first IndyCar championship last season, has struggled in his first Cup season. He failed to qualify at Texas two weeks ago and ranks 38th in the season standings.
Terry Blount covers motorsports for ESPN.com. He can be reached at firstname.lastname@example.org.