The Betfred St Leger at Doncaster appears to be the most likely next port of call for Lambourn after the dual Derby winner's defeat in the Great Voltigeur Stakes at York on Wednesday.
Trainer Aidan O'Brien raised Britain's oldest Classic and the Prix de l'Arc de Triomphe as possible options for his Epsom and Curragh hero prior to his trip to the Knavesmire, but the son of Australia was beaten into fifth place at Group Two level.
The Ballydoyle handler houses the red-hot favourite for the St Leger in Goodwood Cup winner Scandinavia, but Lambourn is also under serious consideration for the Doncaster showpiece on 13 September.
O'Brien said: "The Voltigeur was only a sprint down the straight and was a waste of a race really. They only hacked and it was just a day at the races.
"It is very possible that he will go for the St Leger. He didn't even blow after the race. We just needed to get a race into him."
On the same day Lambourn could be in action at Doncaster, O'Brien plans to saddle Delacroix for what he hopes will be a third successive clash with Ombudsman in the Royal Bahrain Irish Champion Stakes at Leopardstown.
Delacroix was a narrow winner when the pair met in the Coral-Eclipse at Sandown in early July, but Ombudsman turned the tables in a fascinating Juddmonte International on Wednesday after the latter's pacemaker Birr Castle slipped the field before being reeled in late.
Of Delacroix, O'Brien added: "He's good, hopefully it will be back to Leopardstown and hopefully John (Gosden) and Sheikh Mohammed will come (with Ombudsman), we'll have something to look forward to then.
"York was just a Mickey Mouse race really."
