ARCADIA, Calif. — Santa Anita will reopen its main dirt track for limited training Monday nearly a week after the historic racetrack was closed to training and racing in the wake of 21 horses dying since Deb. 26.

Horses can only jog or gallop on the dirt; no timed workouts will be allowed.

“This track is in outstanding condition and it’s ready for training,” veteran track superintendent Dennis Moore said Saturday.

The racetrack remains closed indefinitely for racing.

Moore, along with Mick Peterson of the University of Kentucky’s Agricultural Equine Program, has spent the last few days visually inspecting the one-mile oval, as well as analyzing soil samples and test data.

“It’s been very helpful that we have not had any significant rain since this past Wednesday,” Moore said.

That’s allowed the dirt to be roto-tilled and aerated repeatedly in order to get a uniform consistency on the track’s top cushion, which is six inches deep.

Santa Anita announced new rules to scrutinize horses training on its racetrack and add a director of equine welfare in an effort to mitigate the series of catastrophic breakdowns.

It was supposed to be a huge day of racing Saturday at the rack. But the San Felipe Stakes for 3-year-old Kentucky Derby hopefuls and the Santa Anita Handicap for older horses were scuttled when the track was closed Tuesday.

“What they’re trying to do is the right thing,” said Jim Cassidy, president of the California Thoroughbred Trainers. “Just make sure everybody is accountable for their actions.”

The new rules announced by Santa Anita’s owner TSG include requiring trainers to apply to hold timed workouts for their horses at least 24 hours in advance. Officials believe that will give track veterinarians time to identify potential at-risk horses through their past performances, workout date and physical inspection.

TSG said it has hired extra vets to observe all horses entering and exiting the dirt and turf course during morning training hours.