The 21-year-old was forced to leave the field after just nine minutes against Exeter City on Boxing Day after an industrious challenge from Troy Brown.
Hedges went for a scan following the match and is yet to find out the magnitude of the damage.
Way told YTFC.net: “Ryan is going to be struggling to participate in the foreseeable future.
“We’re waiting for the extent and how long that’s going to be so we’re disappointed.
“It’s disappointing to lose a player of his calibre and we have to make sure someone fills that spot and I’m hoping someone in the group can do that.”
Meanwhile, Matty Dolan and Darren Ward could be contention following their six-week spell on the sidelines.
The pair have been missing since Town’s 2-1 win over Colchester United in November due to hamstring and knee injuries respectively.
“They’ll be coming back soon,” Way said.
“Everyday they get a little bit closer and we look forward to having them back.
“However, I don’t want to rush them and I want to make sure they’re ready.”
Tickets for Town’s match against Pompey can be purchased online or by phone on 01935 847888. Please be aware of our different opening hours over the festive period.