Celtic captain Scott Brown has emerged as a doubt for his side's Champions League qualifier against Linfield, having limped off during a pre-season friendly with Shamrock Rovers.
Brown was forced off just past the half-hour mark at the Tallaght Stadium, going down the tunnel with his knee heavily strapped.
It is another injury blow for Celtic ahead of Friday's Champions League showdown after they also lost Dedryck Boyata to a knee ligament injury during another friendly with Sparta Prague last week.
Boyata is expected to miss three months with the problem, and manager Brendan Rodgers must now wait to see whether Brown's injury is another serious one.
The Scotland international was replaced by Nir Bitton as last season's treble winners thrashed Shamrock Rovers 9-0, with Scott Sinclair and Stuart Armstrong both helping themselves to a couple of goals each.