The Rams travel to Oldham this week with a host of players sidelined, as Greenwood explores ways he can bolster his squad.
Friday’s international match between England and the Combined Nations All Stars has meant Super League clubs are reluctant to let players go out on loan.
Dewsbury have struggled for numbers in recent weeks, with Greenwood describing the situation as “grim”.
“The first challenge is to try and get a team out, before we even think about Oldham,” he said.
“That is what a lot of the work is at the moment, seeing if we can get any of our own players back and then looking to see if we can bring one or two in. It is a grim time.
“All sorts has impacted us; Covid, illness, injury, suspension, loans going back - you name it, we have had it.
“It looks like a lot of teams are going through it. It is not a great season, with everything that is going on. You want to make changes and improve on stuff but it is just about surviving at the moment by trying to get a team out.”
There is no opportunity for the Rams to take games lightly as Greenwood highlighted: “Promotion and relegation has been left in, so every game still means something.”