Hassinger most recently served as assistant to Laura de Seroux and was previously a private trainer for Allen Paulson and The Thoroughbred Corp. He resigned his position with de Seroux earlier this winter to go with Harty and immediately left for Dubai.
"It's good to be back," Hassinger said. "Dubai is a very nice country, but it is nice to be back."
Among the most notable runners in the California-based stable of juveniles – and for the first time older horses – is Tizdubai, a 2-year-old full sister to two-time Breeders' Cup Classic champion and 2000 Horse of the Year Tiznow. The filly sold for $950,000 as a weanling at Keeneland in 2001.
"There's definitely a lot of fast genetics going on there," Hassinger said of the daughter of Cee's Tizzy and Cee's Song.
Harty will shuttle between California and his Arlington Park string, which currently boasts 28 horses of all ages. The conditioner's first runner since returning from the winter in Dubai, Absent Friend, won Friday's fourth race over the Chicago oval, a one-mile maiden special weight event for 3-year-olds and up, by a widening 8 ¼ lengths.