LOUISVILLE, Ky. – It’s usually not a very good betting event when the feature is slotted as Race 2. A short field and/or a huge favorite usually are involved. Both of those factors are definitely in play Tuesday at Churchill Downs, where Kentucky Derby week gets under way in earnest with the $160,000 Isaac Murphy serving as an early focal point of a nine-race card. Lone Rock, whose fabulous record in main-track marathons within the last year makes him an obvious standout, figures in the 1-5 range facing just four other older horses in the second race of the day. Robertino Diodoro, who claimed Lone Rock here in November 2020 for $40,000 on behalf of Flying P Stable and Randy Hill, said he was slightly concerned the 1 1/2-mile Isaac Murphy “might’ve come back a little quick” from the 7-year-old gelding’s latest start, an April 3 victory in the 1 1/2-mile Temperence Hill at Oaklawn Park. :: For the first time ever, our premium past performances are free! Get free Formulator now! “But after his last workout at Keeneland, he came back great,” Diodoro said. “We’re all systems go and we’re gonna give it another shot Tuesday.” That’s troubling news for the rest. Lone Rock has racked up eight wins and two seconds in 11 starts for Diodoro, including a 3 3/4-length jaunt here last year as an odds-on choice in the Murphy. With five subsequent stakes wins to his credit, he’ll surely be singled by untold thousands of bettors in their early multi-race wagers Tuesday. Lone Rock will break from post 1 in the three-turn race with Ramon Vazquez in from his new base in Southern California to ride him for the 10th straight time. Given Lone Rock’s tactical versatility, there will be no need for Diodoro to give Vazquez any advice. “I don’t know the last time I gave Ramon instructions, especially on this horse,” Diodoro said. “He knows the horse better than anyone. He’ll be in charge.” Current (post 2, Chris Emigh) and Hozier (post 5, Flavien Prat) might stick with Lone Rock for a while, but down the stretch the final time this figures as a one-horse race, with maybe Tenfold (post 4, Joel Rosario) chugging along for second. Celerity (post 3, Vincent Cheminaud) rounds out the cast. Diodoro said a repeat in the June 11 Brooklyn, a Grade 2 race he won last year by 11 lengths at Belmont Park, will be next up for Lone Rock. “That’s one of our main goals for the whole year with him,” he said. Diodoro, whose multi-pronged stable has been among the perennial leaders in North America in recent years, is on pace to notch his 3,000th career win by late summer or early fall. The 46-year-old native of western Canada will have a major presence on the Kentucky circuit this year, more so than ever. :: Want to start playing with a $510 bankroll and have access to free Formulator? Learn more “We’ll have 50 to 55 head between Churchill and Ellis Park,” he said. “We’ll stay through the summer, all the way to late November.” The Isaac Murphy is named for the legendary African-American jockey who won three runnings of the Kentucky Derby prior to his death in 1896 at age 35. He was posthumously inducted into the Hall of Fame at its creation in 1955. First post Tuesday is 12:45 p.m. Eastern. Two allowances (races 5 and 8), both scheduled for the turf, are among the better races to follow the Murphy.