Injury has ruled Queensland Derby second favourite Master Of Arts out of Saturday's Group One race at Doomben.

"He is lame in front this afternoon," trainer Darren Weir said.

"We weren't happy with him this morning and he got worse this afternoon, so he's out."

Weir said Master Of Arts, a last-start third in the Grand Prix Stakes, would be spelled.

The Peter Moody-trained Inauguration was an earlier withdrawal from the Derby due to bone chips, clearing the way for first and second emergencies Allzin and Harry to gain starts.

Hugh Bowman takes the ride on Allzin with Zac Purton booked for the Murray Baker-trained Harry.

Werther has tightened his grip on favouritism following Thursday's scratchings and is at $2.30 with Sadler's Lake ($7) and Upham ($9) the only other runners under double-figure odds.