Giorgio Chiellini has warned Juventus that they are "running out of time" to be ready to start their Serie A title defence against Fiorentina on Sunday.
Massimiliano Allegri's side have had mixed results in pre-season, with a win over Tottenham in the International Champions Cup not enough to dispel doubts raised from a penalty shootout defeat to Melbourne Victory and a 2-2 draw with Espanyol.
Juve endured a miserable start to their title defence in 2015-16, taking just three wins from their first 10 matches, before a remarkable run of 26 victories in their final 28 games saw them clinch a fifth Scudetto in a row.
And Chiellini has urged his team-mates to sharpen up this week in order to avoid another disappointing start to the campaign against a strong Fiorentina side in Turin.
"It's a work in progress," he told La Gazzetta dello Sport. "We know we have to improve on the finer details.
"We don't have very much time left and, from tomorrow [Monday], we'll have to give a little extra every day, because it's the details that make the difference.
"We must regain our confidence and return to the right level of focus quickly, because we're running out of time. Our championship starts in a really difficult way and this should give us an extra incentive."
Juve have spent big in the transfer window, signing Gonzalo Higuain, Miralem Pjanic, Marko Pjaca, Medhi Benatia and Dani Alves, while a permanent deal for Mario Lemina has taken their spending to just under EUR158million.
Chiellini says the new arrivals have brought huge positivity to the dressing-room, despite the blow of losing Paul Pogba to Manchester United in a world-record deal, but the Italy international insists that they must not become complacent.
"There's a lot of enthusiasm," he said of his new team-mates. "Compared to the previous summer, we've had less of a change and signed mature, quality players.
"We also got experience after our poor start in the 2015-16 season, when we thought we were giving it 100 per cent, but we weren't.
"We're all veterans and we know the dangers of Serie A. But we have to be aware that, in order to win, we must do more than we've done in pre-season."