Baraweez claimed back-to-back renewals of the prestigious prize in 2014-15 and was fifth last year behind stablemate Dream Walker.
Both horses are in the field once more and will be joined by stablemate Stipulate, while Be Kool is second reserve.
Dream Walker, Baraweez and Stipulate finished third, sixth and 11th respectively in the BMW Mile on Tuesday.
Be Kool was sixth in an extended one-mile handicap on Thursday.
"All of them have come out of their races well," said Ellison.
"Dream Walker ran a blinder the other day and Baraweez wasn't far behind him. Coming back from a mile to seven furlongs will probably suit Baraweez that bit better round here and of the two he's got the better draw, so he might be the one.
"Stipulate missed the break and then got stopped in his run, but that happens around here. You need plenty of luck in running.
"Be Kool ran a good race on Thursday and coming back to seven furlongs won't be a problem for him, if he gets in."
BMW Mile winner Riven Light turns out under a 7lb penalty for Willie Mullins and Declan McDonogh.
Trainer Denis Hogan has high hopes for the bang-in-form Tithonus.
The six-year-old won over the course and distance at last year's Festival and returns at the top of his game, having claimed victory in the Rockingham Handicap and the Scurry Handicap at the Curragh last month.
Hogan said: "He's in good nick and we got lucky with the draw. Stall one over seven furlongs in Galway is worth a length or two, especially for a horse that likes to go forward. He won over seven furlongs here last year, but that was in a lower grade. He was rated 63 then and runs off 96 on Sunday, so it won't be easy.
"But he's obviously in good order at the moment, he seems versatile as regards ground and we're hoping for the best."
Have A Nice Day, Canary Row and Branch Line are others to consider in a wide-open contest.
