Scott Brown has been ruled out of Celtic's trip to RB Leipzig in the Europa League this week, and faces a race to be fit for the BetFred Cup semi-final with Hearts this weekend.
The skipper was forced off midway through this weekend's clash with Hibernian at Parkhead, due a a recurrence of a hamstring injury.
It appears the 33 year old central midfielder may have returned to action slightly too soon; as after missing the defeat to Salzburg and the thrashing of St Johnstone, Brown was unable to complete his comeback appearance against 'Hibs' at the weekend.
This is sure to be a huge blow to Celtic, as their skipper is now likely to miss two of the most important games of their season; a must win Europa League tie away in Germany, as well as a cup semi-final against league title rivals Hearts.
It is understood that Brown did not train with the rest of the Celtic squad at Murrayfield on Tuesday, as they acclimatise to the alternative venue for their cup semi-final, thanks to a nightmare piece of scheduling from the Scottish Players Football Association.
Brown is likely to be replaced by Callum McGregor, who will sit alongside Olivier Ntcham and Tom Rogic to make a three man central midfield for Brendan Rodgers side.