Conte unsure about Costa's future

Antonio Conte says he does not know if Diego Costa will leave Chelsea before the end of the transfer window.

The 27-year-old, who missed Saturday's 3-2 International Champions Cup defeat to Real Madrid in Michigan with a back injury, has been widely linked with a move back to his former club Atletico Madrid.

And Conte dropped a huge hint that the Brazil-born Spain international striker could return to the Vicente Calderon before the transfer window closes on 31 August.

"I can say that today Costa is a Chelsea player," he said.

"He didn't play in these games because of injury and if he solves the injury and I see in training that he is in good shape it can be possible to see him in the next game against Milan.

"But I can say only this. I speak only for today and today Costa is Chelsea's player. Tomorrow if you ask me if Costa will remain with us, I don't know."

Conte was disappointed by Chelsea's performance against Real Madrid, who were 3-0 up at the Michigan Stadium before Eden Hazard netted a consolation brace in front of 105,826 fans, and the Italian says the Blues risk another disappointing season unless the team starts to work together on the pitch.

"I think that this match is very important for us because after this game it's clear that we have to work together always -- without the ball and with the ball -- because if we think that we can't work together when we don't have the ball, it's not possible for us. It's not possible, and we risk to repeat a bad season," he said.

"Today, I think we weren't a team in defensive situations. It's important because in the last game, I appreciated a lot our defensive situation and I told also that we can improve when we have the ball. Today, [we were] better with the ball, but bad without the ball."