Sarri made the move to Turin this summer after one season at Chelsea in which he finished third in the Premier League and won the Europa League.
Speaking after Juves defeat to Spurs, Sarri admitted that his side have a lot to learn ahead of the new season. As quoted by Football Italia, he said: "We need to defend further forward and not so deep. We did better in the second half, with better pressure and 20 minutes of good quality.
"We were naive with the balls we lost, but I think physical condition also counts for something."
Whilst disappointed, Sarri pointed out that their opponents are much further ahead in their pre-season campaign, adding: "It was a difficult game against a renowned team.
"They were quicker and more explosive, but they’re closer to the start of their campaign and closer to the right preparation."
Tottenham will begin their Premier League campaign at home to Aston Villa on August 10th, while the Serie A campaign kicks off two weeks later.
After falling behind, Juventus took the lead against Spurs with two quick goals from Gonzalo Higuain and Cristiano Ronaldo. Lucas Moura levelled things up shortly after and the game looked set to end at 2-2.
That was until Kane pounced on a loose ball to unleash an unbelievable strike from the halfway line to dish out defeat to Juve in their first pre-season fixture.
Sarri will be hoping for a better result in his next game, which comes against Serie A rivals Inter on Wednesday afternoon in Nanjing, China.