Unbeaten champion Frankel will face no more than 11 other runners in the Queen Anne Stakes (Eng-G1), the highlight of the opening day of the famed Royal Ascot meeting next Tuesday, June 19, Racing Post reports.

Frankel, the reigning Cartier European Horse of the Year, began 2012 with a victory in the JLT Lockinge Stakes (Eng-G1) May 19 at Newbury, remaining unbeaten in 11 career starts. The four-year-old Galileo colt, trained by Henry Cecil for Juddmonte Farms, owns six Group 1 victories, including the St. James's Palace Stakes (Eng-G1) last June at Royal Ascot.

Trainer Aidan O'Brien has three runners under consideration to face Frankel in the Queen Anne—Excelebration, So You Think (NZ), and Windsor Palace.

Excelebration is six-for-11 lifetime, with four of his five defeats coming at the hands of Frankel. After beginning this year with a victory in the Big Bad Bob Gladness Stakes (Ire-G3), he finished second to the champion in the Lockinge last time out. The Exceed and Excel colt won last year's Qatar Prix du Moulin de Longchamp (Fr-G1).

So You Think could run in either the Queen Anne, or the Prince of Wales's Stakes (Eng-G1) on Wednesday, June 20. The six-year-old High Chaparral (Ire) horse, is a nine-time Group 1 winner, including two editions of the Tattersalls Gold Cup (Ire-G1). He won this year's edition by six lengths in his most recent start.

Windsor Palace won the High Chaparral E.B.F. Mooresbridge Stakes (Ire-G3) earlier this year, but the seven-year-old Danehill Dancer horse finished sixth in the Lockinge.

Possible to make his 2012 debut in the Queen Anne is Strong Suit, a winner at Royal Ascot each of the last two years. The four-year-old Rahy colt, trained by Richard Hannon, won the 2010 Coventry Stakes (Eng-G2) and last year's Jersey Stakes (Eng-G3).

One notable exception from the potential entries is Cityscape, who finished third in the race last year behind Canford Cliffs and Goldikova (Ire). Cityscape won the Dubai Duty Free (UAE-G1) in March.