The fast but fragile Chief Istan will face the toughest challenge of his undefeated career in the $75,000 Mr. Prospector Stakes at Monmouth Park on Sunday. The six-furlong Mr. Prospector includes another quick front-runner in El Deal, plus Always Sunshine, who is likely to take up a stalking position. Jorge Navarro, the leading trainer at Monmouth, has entered Visionary Ruler and Shaft of Light, who both have good early speed, and Chublicious, who will come from off the pace. Chief Istan, 4, is unbeaten but has started only three times for trainer Larry Jones. At age 2 in 2014, he won a Delaware Park maiden race. He returned seven months later to win a Keeneland allowance by 8 3/4 lengths, earning a 101 Beyer Speed Figure. He was off 13 months before his most recent race, a second-level optional victory in the mud on Preakness Day at Pimlico. “We don’t want to run him too often,” Jones joked. Chief Istan hurt a knee at 2, according to Jones, and was turned out. “He’s just so fast his body gives him some issues,” Jones said. “When we ran him at 3, he hurt the other knee, the same thing. The vet said we don’t need to do anything to it, he’ll be fine, so we turned him out again.” This will be the first time Chief Istan has been able to put races back-to-back. Jones has given Chief Istan two five-furlong works since his May 21 win. “He came out of his last race pretty darn good,” Jones said. “I hope I’m not bringing him back too quick, but it’s been a month, and I worked him a few times. We’re hoping the first race tightened him up.” Mr. Prospector, Race 10 Key contenders Chief Istan, by Istan Last 3 Beyers: 89-101-78 ◗ Chief Istan is owned by Brereton Jones and the Sagamore Farm of Under Armour founder Kevin Plank. Jones’s Airdrie Stud stands Istan, the sire of Chief Istan who from very limited foal crops has sired graded stakes winners Istanford, Albano, and Mr. Bowling in addition to the stakes winner Keep Crossing. Always Sunshine, West Acre Last 3 Beyers: 99-103-104 ◗ He lost a front shoe during the Grade 2 True North in his most recent start, according to trainer Ned Allard, possibly explaining why he lacked a late kick. He should get a good trip from just off the pace. El Deal, by Munnings Last 3 Beyers: 95-82-91 ◗ Won a third-level optional race last out while making his second start following a 10-month layoff. ◗ Trainer Andrew Lakeman has given the mount to West Coast-based Santiago Gonzalez, who is sixth in the Santa Anita rider standings. Gonzalez also rides a Todd Pletcher-trained first-time starter in race 3. Chublicious, by Hey Chub Last 3 Beyers: 96-79-93 ◗ His two quicker stablemates could help set up his late run. ◗ He won the New Jersey-bred John J. Reilly Stakes in his first start for Navarro and owner David Gruskos, who were a bit surprised because they thought he might be a workout or two away from his best. :: Bet Monmouth Park with DRF Bets. Get a $200 cash bonus, including $50 free just for making a deposit! Find out more today