The Celtic defender has been diagnosed with a hamstring tear.
Worringly for Celtic, Jozo Simunovic has pulled out of Bosnia and Herzegovina's World Cup qualifiers with a hamstring tear.
The 23-year-old defender is a huge player for the Hoops and the last thing that manager Brendan Rodgers needs is another injury concern.
Celtic have a massive month ahead of them. First, they visit Bayern Munich in the Champions League, before then facing Hibernian in a League Cup semi-final and then Aberdeen in a top-of-the-Premiership clash at Pittodrie.
Rodgers is already without Scott Brown and Stuart Armstrong for now and losing Simunovic would be far from ideal ahead of such a big run of games.
The Northern Irishman should be concerned - because Celtic fans certainly are.
Simunovic has a hamstring tear??— Roger Moore (@SimpleBlinds67) October 3, 2017
Simunovic has torn his hamstring..? pic.twitter.com/UkN0XrKWjJ— Damien O'Kane (@Damo_) October 3, 2017
Simunovic is made of paper - another CH is essential in January— Pol MacFhionnghaile (@mcginleybhoy) October 3, 2017
Simunovic is injured haha why didn't we sign a CB— Innes (@InnesMac67) October 3, 2017
When you hear that Jozo Simunovic has a hamstring injury pic.twitter.com/FxcBRdwoXr— Sam (@SamuelACasey) October 3, 2017
Not great news. We missed him on Saturday. Hope he heals well and soon— Kirsteen Mosson (@kirstmosson) October 3, 2017
A tear? That’s weeks he is out for then!!— M Daly (@cfcdaly) October 3, 2017
Anyone got any idea how long hamstring tears take to heal? https://t.co/UIJudt2I7p— Jozo Simunovic CSC (@BenTheTim) October 3, 2017
Love big Simunovic but he's a big sicknote. Getting a bit ridiculous now— Paul Sutherland (@PaulSuth) October 3, 2017
For now, it remains to be seen how long the former Dinamo Zagreb man is injured for, but missing the Bayern game might be the big worry.
With him in the side, Celtic conceded five to Paris Saint-Germain and although the big-spending French outfit are a level above their German counterparts at the moment - evident by the fact they beat them 3-0 last week - it doesn't bode well that the Hoops' best centre-back might not be available against the likes of Robert Lewandowski.