Inter Milan midfielder Mateo Kovacic believes losing Arturo Vidal would be a huge blow to Juventus.
Vidal, 27, has been heavily linked with a move away from the Serie A champions this summer, with Manchester United believed to be keen on the midfielder.
Juve coach Massimiliano Allegri has insisted that the Chile international is "not on the market."
Nonetheless, Kovacic believes the other Serie A sides would benefit greatly should Vidal depart Juve this summer.
"If Vidal leaves, then they are going to have lost a lot," he told La Gazzetta dello Sport.
"Arturo is a top player and there are not many central midfielders capable of scoring 10-15 goals and providing 10 assists per season.
"He's a complete player."
Kovacic also feels Inter have more chance of challenging Juventus this season following the resignation of coach Antonio Conte.
Losing Conte makes a considerable difference to a side who have won the last three Serie A titles, according to the Croatia international.
"Even though Allegri is a good coach, without their former coach the Bianconeri have lost something," he said.
Meanwhile, Juventus captain Gianluigi Buffon has spoken of Roma's Serie A title chances this season, believing the capital club to be his side's biggest threat.
"After the season they had last season, they have lots of enthusiasm and the knowledge that they were competitive, and they have strengthened too," he told La Stampa. "On the starting grid, they are level with us."
Buffon also welcomed the arrival of Allegri as Conte's successor, and says he is looking forward to working with the former AC Milan boss.
"There have been lots of changes here, but after a fantastic journey with the same people at the commands, a change is also only natural," he said.
"Allegri has his own type of character and there is no one single way which guarantees success, otherwise it would have been patented."