The 17-year-old, who was Millwall's schoolboy of the year last season, has trained with the first team all week and could be on the bench for Saturday's visit of Preston.
Jackett has drafted O'Brien in with Steve Morison and Neil Harris suspended at the weekend while Kevin Lisbie has an ankle injury and Shaun Batt is a long-term abssentee.
"We've got players like Josh McQoid, John Marquis, Aiden O'Brien and Hameur Bouazza, so the opportunity is there," said Jackett.
Source: PA
Source: PA