Luciano Spalletti was frustrated by Juventus' lack of quality and sharpness but believes his side have more self-belief in the Champions League ahead of the play-offs.
Juventus' spot in the play-offs was secure prior to kick-off against Monaco, and the sides played out a 0-0 draw at Stade Louis-II.
It was a poor performance for Juve, who failed to get any of their five shots on target, and finished the match with 0.2 expected goals (xG) – they ended a run of 37 games in the Champions League with at least one of their efforts hitting the target.
Monaco, meanwhile, had a goal chalked off and missed a brilliant chance after being gifted an opening by Mattia Perin's wayward pass, but the Ligue 1 side clawed their way into the play-offs alongside Juventus.
Spalletti's side are unbeaten in five Champions League games (W3 D2), their longest such run in the competition since March-November 2021 (five wins).
But the Italian head coach believes fatigue played a big part in their lacklustre performance.
"There was some fatigue that started to build up, so I made changes to find some more sharpness and create a better tempo," Spalletti told Sky Sport Italia.
"We didn't manage it, but we were up against a team that kept forcing us to sprint back 100 metres with pace and aggression; their counter-attacks really tire you out.
"Those who came in didn't do badly, but when the quality level of the whole group dropped, so did that of the individual performances."
Juventus failed to win any of their first four matches in the Champions League this term (D3 L1), but finished with three wins and another draw in the final four.
The Bianconeri finished 13th in the league table and will face either Club Brugge or Galatasaray for a place in the last 16.
After that, if they win, they would face a clash with either Liverpool or Tottenham in the knockout-stage proper.
"There is more self-belief now; this is how you go on to prove who you are," Spalletti added.
"We need to give a sense of consistency, but we didn't do it [against Monaco], in terms of tempo, solidity, and playing with width when we did have the ball.
"It was a rough game; they were aggressive, we misplaced too many passes, so there was a lack of quality. We went too slowly, and it gives me something to talk about to the team.
"We did well defensively on their counter-attacks, but from the midfield up, we should've had more quality."