Nineteen days out from what should be his 100th cap for Ireland against Japan, Johnny Sexton is struggling with a hip problem that looks likely to keep him out of Leinster's clash with Glasgow Warriors on Friday.
The captain came off with the problem after 50 minutes of Saturday's win over Scarlets and Leinster say the injury will be "further assessed" today and during the week.
Ireland coach Andy Farrell will be desperate to have Sexton on board for a challenging three-week schedule that sees his side face Japan, New Zealand and Argentina.
As well as the news on Sexton, both Leinster and Ireland will be concerned by James Ryan's latest head injury.
The second-row was replaced after an assessment on Saturday and is following rugby's return to play protocols.
Ryan was stood down from action last spring after suffering repeated concussions and he'll be monitored closely.
Robbie Henshaw is another Ireland star in the wars and the best case scenario is that he comes in cold for the November series after Leinster confirmed he will not be available for Friday night's trup to Scotstoun.
The Lion has a foot injury, but will take a limited part in training this week.
Jack Dunne and Scott Penny are back training and are both available for selection, while Harry Byrne, Dave Kearney and Rory O'Loughlin could all feature if they come through training.
Michael Milne, Will Connors and Thomas Clarkson remain on the long-term injury list.
As two Ulster legends with a combined four Lions tours between them sat in the BBC NI studio at Kingspan Stadium and debated the performance of Nick Timoney in Friday night’s victory over the other Lions, the Ulster back-rower brought to mind a man famous for showing differing shades of red.
United Rugby Championship
Munster head coach Johann van Graan has hailed Joey Carbery's character after the out-half bounced back from a high profile error to nail the winning kick against Connacht at Thomond Park.