Hibernian are facing more defensive problems after skipper David Gray was ruled out for about 12 weeks.
The right-back has been diagnosed with medial ligament damage after a collision with St Johnstone defender Scott Tanser on Saturday.
Gray had missed the start of the season with a knee injury and he joins Tom James and Darren McGregor on the sidelines with Ryan Porteous still to make his comeback from a long-term knee problem.
Paul Heckingbottom said: "It's the same knee but a new injury. As Scott's gone to challenge the lad he has sort of pushed him over and fallen into David's knee.
"It's just one of those freakish things, he has just got over one thing and then another one on top of it.
"We feel for him and it's not ideal for us in terms of a position we are light but we just have to get on with it.
"Last season when we came in we were really light at the back, we had a spell when Darren and Paul (Hanlon) were the only centre-backs available for selection.
"So we have had it before and we will get through it.
"The problem we have had is that David missed pre-season, Lewis (Stevenson) missed pre-season and we have had to throw them back in. Darren is out as well, but we have Ryan coming back who is progressing well.
"So if we can get through the international break and certainly get Ryan and Tom back for selection, we will be pleased."
Porteous was on the bench during Saturday's Easter Road draw but is unlikely to come back in for this weekend's trip to Motherwell.
Heckingbottom said: "He has just missed pre-season so he is medically fit, but physically fit and up to match speed? No, but he will be a while because he has been out for some time.
"Even when we do put Ryan in he won't be at the level he was at before he got injured but he will have to catch up when playing games. But he will be fine, he is looking good."
