Sutton said: "We could have dealt with all three goals better.
"Even though we were 2-0 down at half-time I thought we were still in the game and even when they scored their third just after the break I still thought we were in it because we had opened them up on a couple of occasions.
"We always looked like we were going to score because some of the football we played going forward was good. It was a frustrating afternoon, but I know the players are working as hard as they can and we have to stick at it.
"There's a long way to go this season and we have to keep working hard and I'm sure we will continue to improve."