LOUISVILLE, Ky. – Both the likely field, and perhaps even the likely favorite, for the 139th Kentucky Derby on Saturday at Churchill Downs came into sharper focus Monday, when Code West, Govenor Charlie, Tiz a Minister, and Winning Cause all were officially taken out of consideration for the Derby, and Florida Derby winner Orb turned in an eye-catching workout that, combined with his improving form, may propel him to favoritism over the heretofore acknowledged favorite, the unbeaten Verrazano. [DERBY WATCH: Top 20 Kentucky Derby contenders with odds and video] None of the defections from the field was a surprise. But there was one late surprise Monday afternoon, with Fear the Kitten being added to the prospective lineup. So, as of Monday evening, there were 20 runners known to be likely to enter the Derby on Wednesday morning, with post positions to be drawn Wednesday evening on the NBC Sports Network from 5-6 pm Eastern. A maximum of 20 horses can run in the Derby. If that holds, then the points system instituted this year by Churchill Downs to determine the Derby field if more than 20 enter will not need to be invoked, nor would the old system – based on graded stakes earnings – have been invoked if it was still in force. The biggest smiles on Monday morning were worn by Shug McGaughey, the trainer of Orb, and Dallas Stewart, the trainer of Golden Soul, who moved up the depth chart and into the Derby field because all the defections came from horses ranked higher on the points list than Golden Soul, who has a mere 14 points. Mike Maker, the trainer of Fear the Kitten, announced his intention to run late Monday. Fear the Kitten most recently was fifth in the Blue Grass Stakes. He has 6 points. Alan Garcia has the mount. Orb had looked well in the days leading up to his work, and he gave every indication he is thriving with his drill. He went a half-mile in 47.89 seconds, according to Daily Racing Form, while effortlessly leaving a workmate in his wake, and then galloped out strongly another quarter-mile under exercise rider Jenn Patterson. The work was reminiscent of what both Barbaro (2006) and Street Sense (2007) did in their final drills before their Derby victories. [KENTUCKY DERBY WORKOUTS: Video analysis, news, and times] “I was a little surprised he left his work horse as quickly as he did,” McGaughey said. “The plan was to sit back and go by him at some point. Jenn came back all smiles.” McGaughey said Orb has continued to make progress all year. “This horse has taken me every step,” McGaughey said. “He’s done everything we’ve asked, even a lot more. He’s kept going in the right direction. I’m going into the Derby with the attitude, today, that as of Monday, April the 29th, we’ve done everything possible to make it right, and I think we’ve done everything right. If he draws a bad post, we might have to change our plan. If he has a bad trip, then what will be will be. “I’m excited. I know I’ll get nervous as the week goes on, but I decided I was going to come here excited, try to enjoy the week. I want to enjoy the whole experience.” McGaughey, a native of Kentucky, already is in the Hall of Fame, but, like the late Charlie Whittingham, he only shows up at the Derby when he thinks he has a chance. McGaughey has had just six starters in the Derby, and only one since 1989, when he was second with Easy Goer to the Whittingham-trained Sunday Silence. “The Derby’s at the top of my list. Always has been,” McGaughey said. “And until I win it, it always will be.” [ROAD TO THE KENTUCKY DERBY: Prep races, point standings, replays] Two other Derby runners – both trained by D. Wayne Lukas – worked Monday, both going five furlongs in solo drills. Oxbow was timed in 59.82 seconds, Will Take Charge in 1:00.82. Winning Cause, the Lexington winner, also worked, going a half-mile in 48.46, but trainer Todd Pletcher stuck to his original plan and said Winning Cause would not run back in the Derby, even though he has the points to participate. Pletcher still has five in the race, headed by Verrazano. “He’s 3 for 3 on synthetics, and 0 for 4 on dirt,” Pletcher said of Winning Cause, “and it seemed a lot to ask him to run for the third time in four weeks against what I think is a good Derby field.” Winning Cause is expected to make his next start on Polytrack at Woodbine. Code West and Govenor Charlie also were formally ruled out of the Derby on Monday by trainer Bob Baffert, who had said as much on Sunday. That leaves Baffert without a Derby starter. Tiz a Minister also was removed from consideration for the Derby. The defections Monday at Churchill Downs put Tiz a Minister in the top 20 for points, but his owner, Stephen Young, said Tiz a Minister had emerged from the Snow Chief Stakes at Betfair Hollywood Park on Saturday with “a little bit of a sore foot,” and thus would not travel from California on Tuesday. “We can’t get him ready in time,” Young said. Those defections moved Golden Soul all the way up to 19th on the points list. Stewart was desirous of running in the Derby and welcomed the news, but didn’t want to jinx himself. “I’m a realist,” he said. “I don’t want to be disappointed if someone changes their mind.” It was a cool, cloudy, but dry morning here Monday, and while the Weather Channel forecast is for warmer weather midweek, with highs in the 80s, the long-range forecast for Derby Day is for showers, a 50 percent chance of rain, and a high of just 56 degrees. – additional reporting by Byron King and Mike Welsch