St Johnstone boss Tommy Wright will be without Liam Gordon for around eight weeks after a scan revealed the extent of a knee injury.
The 23-year-old defender suffered the mishap on the training ground during the week.
Gordon also sustained a freak injury to his elbow in training earlier in the season.
Ahead of the trip to Ross County in the Ladbrokes Premiership on Saturday, Wright told SaintsTV: "He went to make a tackle, he is not even in the process of making a tackle and his studs caught on the ground and damaged his knee.
"It is unfortunate, Liam seems to pick up injuries at bad times for him, when he is getting settled and doing well and when there were signs that the partnership with Jason (Kerr) is getting better and better.
"So that is disappointing for him but as always, someone else is going to benefit from that.
"Madis (Vihmann) or Wallace (Duffy) will come in and I am sure either of them will do well.
"It is up to them to go in and stamp authority on the position and claim Liam's place.
"It is really disappointing for Liam but it gives the other centre-backs an opportunity."
The Perth side are bottom of the table with three points from seven games and still searching for their first win as they prepare to take on the Staggies.
Wright said: "It is a massive game for us. We wouldn't and didn't envisage sitting after seven games still searching for the first win.
"Every season I always say it is important to get your first win and get to 10 points quickly and we haven't done that on both accounts.
"It is important to stop this run of defeats and draws and get the first three points for a win on the board."
Defender Scott Tanser insists there is no panic at the Perth club.
He said: "Teams go through stages, everyone has to stick together. No one is going to change it other than us. You have to keep positive. Everyone has got to look forward to playing.
"Everyone knows they have had a good start, we have had the opposite. But we have to concentrate on getting that win."