VIDEO: Sinckler hit with seven-game eye-gouging ban
The 24-year-old British and Irish Lion was cited for making contact with Northampton lock Michael Paterson's eye during a 22-30 defeat in the English Premiership on Sunday.
"I accept the outcome of the hearing and wanted to go on record to say I am sorry that I have let my team-mates down, but more importantly I feel terrible that anyone would think I would deliberately gouge an opponent," said Sinckler in a statement following his disciplinary hearing.
"That was never my intention – it was a genuine mistake and an act of recklessness on my part.
"I will spend the next seven weeks working hard on my fitness and rugby to ensure that when I am able to get back on the field I am fit and ready to do so and make the best possible contribution to Quins,"
Although his ban will end on November 21, four days before England's final November international against Samoa, it is highly unlikely the tight head would be called up on short notice following seven weeks of inactivity.
Sinckler's inclusion in Australian coach Eddie Jones's England squad was far from certain, though, as he was left out of a 33-man training camp last month despite having toured New Zealand with the British and Irish Lions.
Although normally second choice England tight head after Dan Cole, he was picked ahead of the Leicester front row as deputy to Ireland's Tadhg Furlong for the Lions and played in all three Tests.
But now he will miss England's matches against Argentina on November 11, Australia a week later and Samoa on November 25.