MIAMI – The $75,000 Bob Umphrey Turf Sprint has traditionally been a part of the Summit of Speed undercard, as the five-furlong dash fits the theme of Calder’s marquee event just perfectly. But track management opted to break the race out on its own this year to anchor Monday’s special July 4th program, with the weather likely becoming a key component when it comes to both the final makeup and outcome of the race.Heavy rain shut the turf course for business this past week, and the uncertainty over whether the Bob Umphrey would actually be run on the grass is evident from the field the event has attracted. Seven of the 11 horses entered have never won on turf, including the graded stakes-placed You Luckie Mann, Grade 2 winner How’s Your Halo, recent stakes winner Hear Ye Hear Ye, and top sprinters such as Uno Caliente, Peace At Dawn, and Black Diamond Cat.If the race goes as scheduled, proven turf speedsters such as Sir Edgar, Tripski, and Hoopla figure to have the edge.Sir Edgar returns to the grass after setting the pace into the stretch before fading to fourth over the main track in the six-furlong Ponche handicap three weeks ago. Sir Edgar won a $25,000 claiming race going five furlongs over the Gulfstream inner course this winter and was also third after contesting a very fast pace in the Champali overnight stakes here on May 14.Tripski figures to give the speedy Sir Edgar all he can handle during the early stages of the Bob Umphrey while trying to keep his unblemished grass record intact. A 4-year-old son of Trippi, he is unbeaten in three tries on turf, all at five furlongs, including an entry-level optional claiming dash during which he led throughout before hanging on for a neck decision on June 17.A speed duel would enhance the chances of the late-running Hoopla, who brings a modest two-race win streak into his stakes debut. Hoopla rallied to win his entry-level allowance condition by a head going five furlongs on May 28, then stretched out around two turns and showed his versatility by leading throughout to beat second-level optional-claiming and allowance types three weeks later.Uno Caliente is a versatile sort who has registered both career wins on dirt but did turn in the best race of his career finishing second behind the 2009 Umphrey winner, Little Nick, in the Champali.You Luckie Mann has never raced on grass and is not likely to start unless Monday’s main event moves to the dirt. You Luckie Mann, runner-up in the 2009 Carry Back, a Grade 2, started just twice last year, earning his lone win with a 1 1/4-length victory over How’s Your Halo.The racetrack was wet, deep and slow especially before the renovation break on Saturday when Indiano turned in his final prep for Saturday’s Grade 2 Carry Back, going a half-mile in 49.80 seconds. He was one of only four horses to break 50 seconds going four furlongs before the break.The track was still wet but a little quicker after the harrows worked the course, and by the time another Carry Back hopeful, the unbeaten Bulaga worked. Bulaga, a 13-length winner of his only start, went a half- mile in 48.11 seconds before galloping out five-eighths in 1:02.20 for trainer David Fawkes.