Charlie Appleby will wait until next week before making any plans for Masar after a late setback forced him to miss the Coral-Eclipse.
The Investec Derby hero was set to try to supplement his Epsom victory in Sandown’s 10-furlong feature, but was found to be sore following exercise on Friday and was declared a non-runner.
Speaking before racing at Sandown on Saturday, Appleby said he expects to have a better idea of how long his stable star could be out of action for in the middle of the week.
Appleby said: “He is under veterinary care now. The inflammation is coming down and we will be able to get a better diagnosis of what we are dealing with over the next few days.
“All being well, by the middle of next week we should know what we are dealing with and we can then put a timescale on everything.
“Yesterday the soreness and inflammation was there and once we made the decision he was not running, we got the anti-inflammatories in there to get the swelling down.”
He added: “At the end of the day, coming here today was the race everyone was looking forward to. You’ve the Derby form here again and it is the first time the three-year-olds are taking on the older horses.
“I’m very fortunate in who I work for (Sheikh Mohammed). You’ve got to be positive in this game and keep pushing forward.
“Until the middle of next week, I would be giving everyone false impressions if we said the King George or Arc. Until we get next week out the way and know what we are dealing with, I can then give people a race plan.
“The most important thing is the inflammation is coming down.”