Jarrod Bowen struck the winner for the visitors on Boxing Day.
Juric later said, "I think we did a really good game, that we played much better than West Ham and created lots of chances, especially in the first half.
"We didn't score and we conceded one goal where we don't have to concede, but I'm very satisfied that after four or five days of work (in training) the players are starting to press hard, to steal the balls, to shoot a lot on the opponents' goal. There's a lot of things (that I'm happy with) but I'm not happy with the result."
On the team's lack of self-belief so far this season, he continued: "I don't think it's happened this season that the team shoots 18 times and create those kind of chances. I see one very good Southampton, very concrete, with high pressure. The players feel it, they have to adjust to believe and to go on.
"They are listening and they want to improve. Of course, if you have a lot of chances and you don't score, then confidence is a problem."
On task of keeping Southampton in the Premier League, Juric added: "It will be extremely difficult but after today's game, I'm more positive than before because I saw that my players can play better than West Ham - or at the same level. There are a lot of things to getting better, some details, but we have to be confident that we can go on."