Goals from Dan Jones and substitute Jonathan Forte saw the Shrimps come up short at Meadow Lane as they failed to score for the fourth time in five games.
Bentley said: “This was always going to be a difficult game against a big, experienced side and our football was good at times but we just fell a bit short in the final third.
“We did get in a couple of times in the first half but we didn’t take our chances and that proved vital in the end.
“We should have scored from a well-worked corner and then the first time they had a shot on goal their scored from a great free-kick and we were up against it again.
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“Again there were some good signs and we kept plugging away and it was another game for the new lads to get to know our system and they will keep getting better.
“We know it is a results-based business and we know we need to start getting goals and picking up points but there are some good signs that we have to build on.
“We all have to stick together and keep working hard and hope we get a little bit of luck that I think we deserve.
“We haven’t been hammered by anyone and we have been in every game we have played and we just need to work hard to turn things round.’’