AC Milan defender Daniele Bonera says the players must be united behind coach Massimiliano Allegri during this difficult preseason.

Bonera admits the departure of Thiago Silva for PSG is a blow.

"He is a major loss. The club have done their own evaluations and there are still many days left until the end of the market, soon enough we can be as competitive as ever," the 31-year-old said.

"The departure of important players like Ibra and Thiago is regretful for all, but over the years Milan has always provided its Coaches with competitive squads.

"I have heard that Ibra and Thiago are disappointed that they are going, they know they are leaving a place where they were happy and that they have contributed at for years.

"The fact we have lost so many players makes everything seem dark. The impact of losing Thiago may not have been so bad if we still had [Alessandro] Nesta.

"For me, it's a disappointment to lose so many teammates with whom I shared many moments. Now, who is left must understand the spirit and values of Milan, to help the Coach, and we must all work together."