The German believes that in-demand Rudiger knows how valued he is at Chelsea - but also that he remains focused on the "toughest challenge" of the Premier League. hummel survetement Doidge is back in full training after an Achilles injury back in August and could make his return in Sunday's League Cup semi-final against Rangers at Hampden Park. hummel survetement The 29-year-old has signed a two-year extension to his previous deal, which was due to expire next summer. hummel survetement Coltart: "Everybody has got to have a game on the opening day, for me, and fourballs is massive in the afternoon. I'd put together two steady performers and two of the best drivers in the world. They're two Englishman, who know each other incredibly well, and are very comfortable in these situations." hummel survetement