Clive Cox believes there is plenty more to come from Diligent Harry as he prepares for the Ladbrokes 3 Year Old All-Weather Championships Conditions Stakes at Lingfield.
Winner of his first two starts, Diligent Harry was a fast-finishing second last time out - and although he surrendered his unbeaten record, he lost little in defeat.
He is set to be in action against his contemporaries on Friday, and Cox said: "He's progressive.
"After two easy maiden and novice starts, that was a step forward last time out even though he was second.
"I do think he's still on an upward curve, and I certainly hope he is."
Diligent Harry has displayed plenty of pace so far, and his Lambourn trainer added: "He's got a lot of potential and scope there, and he's still very much learning his job - but because of that, he's entitled to find more progress, I think.
"He's very quick - we did drop him back to five furlongs for his second outing, but that was more because the opportunity arose more than being a necessity.
"I think six furlongs is where we want to be with him at the moment.
"He's taking on another notch of top-class horses, so we need to see more progress, but we're hopeful he is progressing in the right direction to take the next step."