Beags has been struggling with a hamstring injury over the past couple of weeks, and despite sitting out last week's Worthington Cup defeat at Preston North End aggravated it again on Saturday when Kiddy Harriers were in town.
Speaking after the match Iron manager Brian Laws confirmed that Beags would have to sit out, but also that the club will have to monitor Matthew Sparrow and Andy Dawson.
"Peter is definately out for Tuesday, he has worked ever so hard this week and we thought it was enough. But it wasn't," said Laws.