Defeat to Tottenham saw Saints' expected relegation confirmed on Sunday.
Reflecting on the campaign, Juric says the quality of Southampton's squad fell short of Premier League standards.
"Recruitment is everything in football," said Juric.
"We have a lot of talented young players, but with not many games in the Premier League. What I noticed most in three or four months here is the completely different physicality between us and the other teams in the league.
"Now is the moment to understand the mistakes the club made in the last three or four years and start to create something really good."
On the Saints support, Juric also said: "The love they show is incredible.
"They deserve more. Every person that works at Southampton has to do better and create something stronger."