Fleetwood have denied on-loan Davies permission to play at The Crabble while Arestidou picked up an ankle injury in his first day back training after recovering from a stomach problem.
Shrimps boss Jim Bentley however is set to draft in a second stopper on loan ahead of the trip south.
He said: ”We’ve had a bit of bad luck.
“After Barry Roche’s injury we brought in Scott Davies on loan from Fleetwood and unfortunately they don’t want him cup tied.
“But the other big one is Andreas Arestidou, who we thought would have been fit by now.
“He had a stomach problem and has thankfully got over that with a couple of weeks rest but in his first day back training while making a save he caught his foot in the turf and rolled his ankle.
“We thought if Scott was cup tied we’d have Andreas ready to come in and play but unfortunately we now need another goalkeeper to come in.
“Such is life, we’ll get one in ready for Saturday and he’ll probably be here for a few weeks on the bench while Andreas is out.
“We’ve got a couple of options and we’ll certainly have one in the next 24 or 48 hours.”