Homestead, Fla. ? A new year has brought another challenge for two-time defending Indy Racing League champion Sam Hornish Jr.

A year ago, it was the elite Marlboro Team Penske — switching from the CART series to the IRL — that posed a new problem for Hornish and his Pennzoil Panther Racing team.

Gil de Ferran, coming off two straight CART championships, and Helio Castroneves, the 2001 Indianapolis 500 winner, were supposed to put the precocious Hornish in his place.

It didn’t happen. The 23-year-old Hornish fought off a midseason slump and relegated Castroneves, who won Indy again, and de Ferran to second and third in the 2002 IndyCar Series.

Now, heading into Sunday’s season-opening Toyota Indy 300 at Homestead-Miami Speedway, there are a whole new set of obstacles facing Hornish.

Not only is everyone in the series starting with all new cars and engines, but more of the top teams from the CART series have made the switch to the IRL.

That includes Andretti-Green Racing, with longtime open-wheel standout Michael Andretti and CART stars Dario Franchitti and Tony Kanaan as its drivers.

Then there is four-time CART champion and 2000 Indy winner (with Juan Montoya) Chip Ganassi Racing, which has shown up with two chargers of its own — Scott Dixon and Tomas Scheckter.

Team Rahal, which will continue with one car in CART, is taking a run at the IRL with 1999 champion Kenny Brack, who has spent the past three seasons in CART. Morris Nunn Racing is focusing its complete attention on the IRL this season, expanding a one-car effort to include returning Felipe Giaffone and former Formula One driver Tora Takagi.

Scott Sharp, an IRL regular since it began competition in 1996, said preseason testing has been an eye-opener.

“This race is going to be awesome, as will every race this year,” Sharp said.