DEL MAR, Calif. – Ain’t Easy on Monday morning at Del Mar was not entered in Friday’s Breeders’ Cup Juvenile Fillies when she failed to jog to the satisfaction of trainer Phil D’Amato, and her jockey, Joel Rosario, was quickly snapped up by trainer Steve Asmussen for race favorite Echo Zulu. Ain’t Easy has won both her races, including the Chandelier Stakes at Santa Anita in her last start. She had gone to the track for routine training on Monday after working on Saturday, but was jogged later and was “not 100 percent,” D’Amato said. “We’re going to have to do some diagnostics. We don’t know what it is yet,” he said. “She usually jogs smooth as a gazelle, but she doesn’t look as smooth as a gazelle. We have to figure out what’s wrong.” Her defection left Rosario without a mount, but only for a moment. Even though Ricardo Santana Jr. has ridden Echo Zulu to wins in all her starts, Asmussen said he decided to go for the suddenly available Rosario because of his experience at Del Mar. Rosario led the standings here three straight summers from 2009-2011 when based in Southern California, and though based elsewhere in recent years often returns to ride and win a number of major stakes. “Where the race is run,” Asmussen replied when asked why Rosario was a better fit for this race. The Breeders’ Cup Juvenile Fillies, at 1 1/16 miles, will mark Echo Zulu’s first race around two turns. :: BREEDERS’ CUP 2021: See DRF’s special section with top contenders, odds, comments, news, and more for each division Only nine were pre-entered in the Juvenile Fillies, and only six were were expected to run. In addition to Ain’t Easy’s defection, Nest did not travel from New York, and two-time grass winner Cairo Memories will remain on turf in the Juvenile Fillies Turf on Friday. Entries were due Monday morning, with posts to be drawn Monday afternoon. The Juvenile Fillies field was expected to be Desert Dawn (Ricky Gonzalez), Echo Zulu (Joel Rosario), Hidden Connection (Reylu Gutierrez), Juju’s Map (Florent Geroux), Sequist (Junior Alvarado), and Tarabi (Javier Castellano). --additional reporting by David Grening