According to Sky Sports News, the Blues are interested in signing the Italy international following the sale of Cesc Fabregas to Monaco. The report said Cagliari value the 21-year-old playmaker at around £45 million.
However, Passetti has said the Serie A side will do what they can to keep Barella at the club for now, although he appears resigned to losing him in the summer, per Rai Sport (h/t Football Italia):
"We continue to talk about him, we do interviews and issue statements, but evidently we're not being clear enough: we reiterate that he'll stay for at least for the next six months.
"After that, we'll see what happens in the summer. We have big ambitions and Nicolo gives 1,000 percent in every training session and he's happy to be at Cagliari. Selling him isn't one of our objectives."
Barella has developed into one of the most exciting midfielders in Italian football over the last couple of years. In the previous term, he cemented his status as a regular in the Cagliari XI, and in 2018-19, he's been the standout performer in a struggling team.
The Italian has also shown early in his career that he has a lot of facets to his game, making him a useful player to have around the squad. Italian football journalist David Amoyal broke down some of his best qualities:
David Amoyal @DavidAmoyal
Barella is a very dynamic modern midfielder. He’s versatile, great at getting ball back but also gets between the lines offensively and has a powerful shot. Has similar attributes to Allan but would say he doesn’t have as much pace & tactical intelligence but scores more goals https://t.co/EbOFX3vEz2
In the Italian top flight this season, Barella only has one goal and no assists from his 17 games, but in the previous campaign, he chipped in with six goals and an assist.
There's more to his game than marauding forward, though. Despite his elegance and technical quality, Barella is not a footballer who shirks his defensive responsibilities:
Chelsea would benefit from adding another forceful presence in central midfield, as they have been a little one-dimensional at times in this area of the pitch.
N'Golo Kante and Jorginho have both performed well in the main, but Mateo Kovacic and Ross Barkley have been inconsistent. Ruben Loftus-Cheek is also sidelined with an injury at the moment.
As journalist Dan Levene noted during Chelsea's recent 2-1 win over Newcastle United, the team often has possession with little penetration:
Cagliari seem adamant they will not lose Barella in the January window, although an offer in the region of £45 million would surely be tempting. After all, they appear set for a midtable finish in Serie A, as they sit seven points clear of the relegation zone and 10 points behind sixth.
Chelsea may feel as though they can push Cagliari into a sale as a result, although the Italian outfit going back on their word at this point may not be well received by supporters.