Beckford sustained a hamstring injury in the recent win at Barnsley and missed the weekend home defeat to Brighton, while Scannell missed out due to a similar problem.
"Jermaine was close to playing (against Brighton)," Grayson said. "But we just felt that it's too big a risk to employ him in the game when his hamstring might go and then he'd be out for a long period of time.
"Sean Scannell had a tight hamstring from Thursday's training, hence why we left him out of the squad as well. You have to look at the bigger picture sometimes.
"I would think Jermaine and Sean have a strong chance for next weekend because they weren't too far away. We'll assess them on a daily basis and we're hopeful, but you're never sure with these types of injuries. If there is a slight danger of them missing all the games over the festive period, we won't risk them."
Grayson added that fellow striker James Vaughan, who has missed the last five games due to a thigh injury, will go for a scan on Monday to assess how he has responded to treatment.