Kieren Fallon will miss the Guineas meeting at Newmarket later in April despite being partially successful in his appeal against a 10-day riding ban.
The former champion jockey was suspended after Kempton stewards found him guilty of not riding out to the winning line on on 13 April.
The jockey was originally sidelined between 27 April and 6 May but had his ban reduced to seven days on Thursday.
The news confirms Fallon misses the ride on Ed Dunlop's Native Khan.
Fallon recently guided the colt to an impressive comeback victory in the Craven Stakes.
The six-time champion jockey had his appeal heard at the British Horseracing Authority headquarters and the disciplinary panel downgraded his suspension, meaning he will be banned until 3 May.
The 2,000 Guineas is on 30 April while the 1,000 Guineas is a day later.
Fallon, riding Sukhothai, was caught for second place in the final stride by the fast-finishing Watered Silk.
The British Horseracing Authority ruled in a statement: "The panel found that Fallon failed to ride out approaching the finish and therefore had not taken all reasonable and permissible measures to ensure his horse ran on its merits, but were not satisfied that Sukhothai would have finished second if ridden out."
Grand National-winning rider Jason Maguire was successful in his appeal against a 10-day riding ban handed out for taking the wrong course at Wetherby on Sunday.
Maguire said he had taken evasive action to avoid the injured Harry Haynes, who was still being treated after a fall on the previous circuit.