The training season for the start of the Monmouth Park thoroughbred meet is under way.

The season officially started early Monday when a van carry three thoroughbred horses trained by Gregg Sacco arrived at the track at 6:25 a.m. Some 1,600 horses will be stabled at the Jersey shore track during the meet, which will open on May 14.

The meet will be highlighted by the $1 million Haskell Invitational, set for July 31. Other graded stakes highlights include the United Nations Stakes on July 2, the Iselin on Aug. 20, and the Molly Pitcher on Aug. 28.

Other early arrivals on Monday included horses from the Henry Carroll barn as well as a group from the Chuck Spina.

Sacco, a third generation horsemen, won 20 races last season at Monmouth. Among those returning from his barn in 2011 is Unbridled Essence, winner of last year’s Grade 3 Matchmaker Stakes on Haskell Day.