Conte keeps Costa guessing over Cup role

club Tianjin Quanjian, who have confirmed they are still working on a deal to sign him in the summer.

There are fears that Tianjin’s interest and his unhappiness in England have affected Costa’s form since the turn of the year, although he did play with a stomach bug in last week’s defeat by Manchester United.

Costa will have two years remaining on his contract at the end of this season, when the club will have to decide whether to offer him a new deal or sell him.

Leaving him out of the semi-final would only strengthen the growing feeling that Costa is likely to be sold, with Chelsea lining up bids for Everton striker Romelu Lukaku and Alexis Sánchez of Arsenal.

Conte confirmed that Cahill spent two nights in hospital this week with gastroenteritis and will not be part of his squad, but goalkeeper Thibaut Courtois has recovered from an ankle injury to play.

Terry this week confirmed that he would leave Chelsea at the end of the season, but Conte will replace Cahill with Ake in his back three.

Ake has made only two appearances for Chelsea since being recalled from his Bournemouth loan in January and Conte said: “Ake deserves to have this chance to play because he is showing me in all this period always a great commitment. “He worked very hard. His behaviour was great, was fantastic, and he never said nothing. And don’t forget that Ake was playing every game with Bournemouth and he wanted to come and to stay with us to try to work together and to help us to fight for the title. I think he’s a good player. “He’s ready to have this chance, he deserves this opportunity and I trust him. I have no problem to take this decision.”

Asked why Terry would not start, Conte added: “I think in this system the right position [for John] is in the middle of the three central defenders. In this case, Ake has the right characteristic to be the substitute for Gary and the same [Kurt] Zouma for [César] Azpilicueta.”