Don & Sir Des all set for the Lexus Don Poli and Sir Des Champs form a formidable twin assault for Willie Mullins as the champion trainer bids to finally break his duck in the Lexus Chase at Leopardstown. The prestigious event is one of the few Grade Ones to so far elude the master of Closutton, but the betting suggests it would be a major surprise if the run is not brought to an end on Monday. Last season's RSA Chase hero Don Poli is the odds-on favourite after impressing on his seasonal reappearance at Aintree. However, Sir Des Champs, a dual Cheltenham Festival winner and runner-up in the 2013 Gold Cup, was a comprehensive winner on his return from a near-two-year absence at Thurles last month and Mullins feels he should not be dismissed. He said: "Don Poli is in good form and Sir Des Champs is fine as well. It's not our luckiest race, but hopefully one of them might do it. "Other years before the race we've thought we'd had good chances, but we've as good a chance as we've ever had. "Don Poli may be the favourite, but don't forget Sir Des Champs has been second in a Gold Cup, and Don Poli has not been at that level yet." Gigginstown House Stud's retained rider Bryan Cooper has unsurprisingly sided with Don Poli of the pair, leaving stable jockey Ruby Walsh free to ride Sir Des Champs for the first time. Gigginstown have a third representative in the form of First Lieutenant. Mouse Morris' charge ran a fine race to finish third in the Hennessy Gold Cup at Newbury last month, but has plenty on his plate at level weights with some of Ireland's top chasers. Morris said: "We looked at running him in the Paddy Power Chase, but he had too much weight and I didn't want to run him with a big weight round there in bottomless ground. This is going to be tough, but we'll give him a run round and see what he can do." The Ted Walsh-trained Foxrock has finished in the first three on five of his six visits to Leopardstown, most recently finishing second in last season's Hennessy Gold Cup. However, he has been well beaten twice this season and connections reach for the blinkers in an attempt to reinvigorate the seven-year-old. Owner Barry Connell said: " I haven't a clue what to expect, to be honest. If he runs the way he did the last day he'd have no chance, but if he ran the way he did in the Irish Hennessy last season, he would have a chance, so it just depends which horse turns up. "We're hoping the return to Leopardstown will help him as he's run well there a few times. We're also putting some blinkers on him, so hopefully that might help, but you couldn't bank on him after the way he ran last time." John Kiely's Irish Hennessy winner Carlingford Lough returns to chasing after finishing tailed off on his seasonal debut over hurdles at Navan. The five-runner field is completed by Mullins-trained veteran On His Own, ridden by the trainer's son Patrick.