The pair missed the 2-2 draw at Ebbsfleet United on Saturday, having started in the 1-0 victory over Braintree Town last weekend.
Speaking after Saturday’s game, McNulty commented:
They’re two big losses,” he said.
“Both of them suffered muscle injuries this week. We’ve had them scanned and they’re [both out for] six weeks, which is a shame, a loss.
“The rest of our squad has to step up. Luke has been outstanding for us, but Dave [David Robson] has done well when he’s come in. Luke has achieved a brilliant stat in terms of clean sheets and is a loss.
“Dev is Dev. We’re talking about Devante Rodney, any team that misses him in this league would feel it. We missed him for a large part of last season, and we’ll feel that again.
“But the guys are ready to step up and do what’s right for the team. I thought Leon Ayinde was brilliant today, he ran himself into the ground and I had a slight muscle concern over him in the latter stages, so had to make a change really sharply as his hamstring was tight.”
The pair join an increasing injury list, with Ethan Ebanks-Landell, Harvey Gilmour and Dan Sassi also out of action.