The Reds are next in action at home to Swansea City on Saturday 30th March, as they target a top six spot in the Championship.
A 1-1 draw away at bottom side Ipswich Town last Saturday saw Martin O’Neill’s men three points adrift with eight yet to play.
Cash said: “We have just got to keep working. We have the break now so we just have to come back refreshed.
“A lot of the lads have played a lot of minutes so it will be good to have a nice break in, refresh the legs and come back really fresh for the last few games.
“These last few games are so important; we are all fighting so we have got to keep going.”
Forest were denied the win at Portman Road when Daryl Murphy’s goal was incorrectly ruled out for offside.
“It was a frustrating day,” said Cash, returning to the matchday squad after injury.
“Obviously it was nice to be back on the pitch myself. I thought we played well in some patches and we were unlucky as the referee’s decision has cost us. We have watched it back and it was not offside.
“We came here to try and get the three points. Unfortunately we didn’t, we picked up a point and we have to move into the next game, regroup and stay strong together.
“We are still three points off the play-offs. It is frustrating as we are so close and we just want to get as many points as possible. We have got to kick on and anything can happen in these last eight games.”