Roger Varian's grey has won three of his previous starts and was a best-priced 5/1 chance for the feature event on the first day of the Flat turf season on Town Moor.
However, the Kremlin House handler ruled out his charge shorty before declaration time.
Varian posted on Twitter: "Unfortunately, Morando will not run in the Lincoln Handicap @DoncasterRaces on Saturday having incurred a minor setback this morning."
A maximum field of 22 will go to post for the fiercely competitive handicap, with John Ryan's Battle Of Marathon heading the weights.
Leading contenders include Roger Charlton's Yuften - Sky Bet's new market leader - the Robert Eddery-trained Donncha and Bravery from David O'Meara's yard.
Gabrial, the winner two years ago, is part of a formidable challenge for Richard Fahey, with stable companions Third Time Lucky, Heaven's Guest, Dolphin Vista and Withernsea all in the final field.
Brian Ellison is double-handed with the popular Top Notch Tonto and Dream Walker.
The Martyn Meade-trained Chelsea Lad, heavily backed during the week, is a notable absentee after he failed to make the cut.
Yuften was handed stall 14 at the draw ceremony. The first horse out of the hat was Amanda Perrett's Zhui Feng, who was given stall 13, while the last out was Third Time Lucky in stall one.
Donncha is near the stands rail in stall 21, while Bravery breaks from gate 20. Top Notch Tonto will come out of stall eight, with Dream Walker alongside him in nine. Ryan Moore's mount, the Richard Hannon-trained Oh This Us, will race from gate two.
Sky Bet odds: 9/2 Yuften 7/1 Donncha 9/1 Top Notch Tonto 12/1 Bravery 14/1 Battle Of Marathon, Dolphin Vista, Oh This Is Us, Zhui Feng, Third Time Lucky. (correct at time of publication).
