Time is against Darley trainer Peter Snowden getting unbeaten colt Safeguard ready for the Golden Slipper.

Identified as a genuine Golden Slipper chance on the strength of a first-up Flemington win in December, Safeguard's preparation is behind schedule because of a minor temperature spike last week.

"He had a temp last Monday week and it has taken him probably a full week to recover from it," Snowden told Sky Sports Radio.

"Naturally a week's work at this time of the year is vital and he's going to be pushing it to make the Slipper."

Safeguard drifted from $17 to $26 in Golden Slipper betting immediately following Snowden's admission.

The colt's likely defection from the Slipper leaves the filly Guelph as the highest-rated Darley runner in updated betting charts.

Guelph is a $26 chance who will be trying to restore her Slipper credentials in a Randwick barrier trial next Friday.

"It will be a nice hit-out for her two weeks before the Slipper and she will go straight into the race from there," Snowden said.

At her most recent start, Guelph finished unplaced for the first time in her career when ninth to Miracles Of Life in the Blue Diamond Stakes.