The filly carries the colours of Andrew Tinkler – boss of the Eddie Stobart haulage firm – who has invested huge sums in bloodstock this year.
His horses are in the care of Michael Dodds and the County Durham trainer saddles Miss Mediator for the Matrix EBF Maiden Stakes (7.55pm) on the East Lothian track
The filly is a half sister to a good winner in American and Tinkler forked out 160,000 guineas for her at the breeze-up sales at Newmarket in April and the youngster went close to giving him an immediate return on Knavesmire.
Always up with the pace, she perhaps ran a bit too free but led briefly entering the final furlong before failing to quicken again near the finish and was beaten just a length into third place.
She will have learned a great deal from that experience, has a decent draw near the rails tonight and can make all the running.
Ross Birkett is a more-than-capable amateur jockey, who has scored twice in the past on Sand Repeal and the partnership can win the opening Bollinger Champagne Series Handicap (6.55pm).
Those two victories came over a mile and a half at Windsor and Chester in 2008 but the eight-year-old stays this two-mile trip well and Birkett has also been placed on him on several occasions. The long trek from Julie Fielden's small Newmarket yard can pay off. Silvanus can pull hard, but Paul Hanagan found the key to the gelding when steering him to victory at Carlisle a month ago and although the five-year-old has been beaten since, he was far from disgraced when runner-up under a different pilot at Wolverhampton.
All four of his career wins have come over the minimum trip – including one over course and distance last summer – and Hanagan can steer him home again in the Matrix Handicap (7.25pm)
Hanagan is fighting out with champion Ryan Moore at the top of the jockey's table and can complete a double on Grand Diamond in the Nairn's Oatcakes Handicap (8.25pm).
Both his career wins have come on this track and he is a regular on the seaside circuit where he has also been placed on several occasions. Those wins were achieved at around a mile but he is developing stamina with age and was placed three times over hurdles last winter.
The six-year-old was an excellent second over ten furlongs at Ayr recently and the winner there has scored again to boost the form, so the step up to a mile and a half may not stop him from going one better.
Joe Rowntree's Musselburgh selections: 6.55: Sand Repeal; 7.25: Silvanus; 7.55: Miss Mediator; 8.25: Grand Diamond.