Group One-winning mare First Seal is likely to kick off her spring campaign in the Warwick Stakes before heading towards the Epsom Handicap.

Trainer John Thompson rates her as a strong chance in the race, where she is among 13 Group One winners entered in Saturday's Group Two weight-for-age feature at Randwick.

Thompson said the mare has matured in the lead up to her first run as a four-year-old.

"She was always a big, strong filly, but just with a couple of good racing preps she seems more seasoned," Thompson said.

"She'll improve off the run, but you'd expect her to be running first three."

Thompson's confidence in the mare improved further after a track gallop on Tuesday morning, when ridden by Christian Reith.

"She worked solidly this morning over six furlongs (1200m) with a mate and it was nice strong work. Christian Reith galloped her for me and he said she gave him a great feel," Thompson told RSN.

If First Seal heads to the Epsom it won't be the first time Thompson has set the mare for a blue riband group one, something that has eluded the daughter of Fastnet Rock thus far.

Her only Group One win came in the Flight Stakes as a three-year-old when she eased to a three-length win over Winx. Since then she has struggled to win another.

Blown away as a three-year-old by Hampton Court in the Spring Champion Stakes, at four she was bloused by a driving Plucky Belle in the Coolmore Classic and again in the Vinery Stud by Fenway, before struggling to sixth in Amanpour's Queen of the Turf.

The only thing that could disrupt Thompson's plans to tackle the Epsom is wet tracks.

While she was a Group Two-winner on soft ground when taking out the 2014 Surround Stakes, Thompson says he will not run her on a heavy track.

"There's a bit of rain predicted during the week, but I think we'll be pretty fine for Saturday," he said.

The final field for the Randwick feature will be decided on Wednesday morning.

If Sydney endures a wet Spring Thompson would target the Sir Rupert Clarke Stakes and Toorak handicap with First Seal.