MIKE BROWN appears increasingly unlikely to play in England's pivotal RBS 6 Nations clash against Ireland this Sunday following a setback in his recovery from concussion.
Brown felt a recurrence of his symptoms over the weekend after being knocked unconscious in the 47-17 victory over Italy and having completed a weekend of rest has restarted the return to play protocols.
The earliest the Harlequins full-back will be able to resume contact training is Friday.
"It's very early for me to pencil Mike in for a game at the moment," Lancaster said at the squad's Pennyhill Park training base.
"We don't know how it is going to play out because he's done stage one of the process on Monday and there could be a reaction. That will have an implication, big time," said England head coach Stuart Lancaster.