Mansfield Town look set to be without injured skipper and centre half Krystian Pearce for the visit of Colchester United on Saturday.
But, with Matt Preston fit again, they have a ready-made replacement.
Dempster said: “I think it will be touch and go for Krystian this weekend. He’s got a low grade strain in his groin.
“He was keen to play on at Walsall but I think we made the right call with that one, having spoken to the medical team.
“We are very fortunate to have the cover of Matt Preston, who I believe is one of the best centre backs in League Two and could probably play higher.
“It shows our strength in depth and it is an opportunity for him to come into the team and perform like he did when he came off the bench at Walsall.
“But the sooner we can get KP back the better of course as he’s been colossal over the last few years for the football club and he is a big character in the dressing room.”
Fellow defender Hayden White has been resting up the leg he broke earlier this year which has been causing him pain, but is now close to a return.
“We will see how Hayden White is this week. He will have a full week’s training,” said Dempster.
“I am not sure if he will be available for selection for the weekend but he’s right on the brink of being back to full fitness and being pain-free, which is key.”
However, Stags should have midfielder Jacob Mellis available for the squad.
“Jacob Mellis will train all week,” said Dempster. “We were keen he had a full week’s training. He only did three or four days last week.
“I expect him to be in contention on Saturday.”
On striker Danny Rose, he said news continued to be promising.
“Danny is progressing very well,” said the manager. “The original assessment said four to six weeks, we are now hoping it will be a bit sooner. It’s certainly looking more like four now.
“It will just depend on how he does in his rehab and how his ankle reacts to the treatment.”