The Iron lost 4-1 to Argyle at home and Horsfield is now focussed on making sure the team performance is better this weekend.
“I’m obviously very, very disappointed for all of us and the fans that came to watch,” Horsfield told iFollow Iron.
“It was not the result we wanted, but we are going to have to pick ourselves up and look forward to next Saturday.
“It is difficult for the side, but we cannot dwell on it and we need to give everything on Saturday.”
United could have made it 2-2 at the beginning of the second-half when Lee Novak forced Plymouth goalkeeper Matt Macey into a good stop, before Ike Ugbo’s goal was ruled out for offside.
Horsfield said: “I felt like another goal was coming and it could have gone 2-2 quite easily, then we are here talking about a different game.
“We went 1-0 down and we started to play a little bit after they scored. We then conceded a sloppy goal just before half-time.
“We came back out, going for it, got a goal and the fans got behind us.
“I felt like there was something there for us, but we conceded another sloppy goal.”
On starting the game, he said: “Personally, I was very happy to play, but it is a team game and I am very disappointed we have lost the game."
Horsfield stressed the importance of getting a result at Glanford Park on Saturday when Oxford United are the visitors.
He added: “We have got to give everything on the pitch, pull together and get a massive result here.”
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