Ireland back Rob Kearney has become an injury doubt for their November Tests after suffering a back injury that could sideline him for up to six weeks.
The British & Irish Lions hopeful was forced off in Leinster's defeat to Connacht last weekend after taking a heavy tackle while taking a mark.
Kearney will not play in this week's RaboDirect PRO12 clash with Munster at the Aviva Stadium, with coach Joe Schmidt hoping the injury heals.
"There's no major damage with Rob," said Schmidt, whose side have lost twice this term.
"He's very uncomfortable. There's quite a bad haematoma there, with that bad blood being a real irritant, and hopefully as that drains away he should come right quite quickly.
"He won't be available for Munster but maybe beyond that we'd cross our fingers."