Diego Costa quality will shock Chelsea's rivals, says John Terry

John Terry believes Diego Costa will surprise people with how good he is, and that not even the Chelsea squad properly realised until they trained with him.

Costa scored the key first goal in his side’s 2-0 win over Leicester City on Saturday, following on from his equaliser against Burnley in Monday’s 3-1 victory. A tally of two in two games has already helped to begin quashing arguments that he may be another expensive Chelsea striking flop. Terry has no doubt he will be a success, and insists there is plenty more to come from the former Atletico Madrid attacker.

“I didn’t realise how good he was even after playing against him in the Champions League,” the Chelsea captain said. “You will see that once the full fitness comes. There is still more to come from him. He has caused us some problems in training. He has been unbelievable.

“When they hand the bibs out you want him to be on your side. He looks ready-made for the Premier League. He can handle himself well.

“Myself and [Gary Cahill] gave him some grief at Atletico away but he stood up to us and he fancied it. He has got that to his game but, the other side of his game, we will all be surprised at just how good he is.

“He is quick, powerful and, more importantly, can score goals. It was great for him to get off the mark here and get a great reception from the fans.

“It’s about being in the right place at the right time and the one at Burnley summed it up,” Terry added. “It came off the post and there he was.

“He is very good. He has come in pre-season and he has scored goals. He’s been great around the dressing room without speaking any English. He is kind of quite funny because he gets on and gets his way around the dressing room and everyone helps out and translates. I am trying to teach him some words in English. He has settled in off the pitch and the goals have obviously helped.”

Chelsea manager Jose Mourinho thinks football could do more to help itself – by allowing time-outs. Having complained after the victory over Leicester – in which Eden Hazard scored the second goal – that his players were “lazy”, Mourinho said managers should be granted one intervention per half. That, he said, would improve the game, and might have allowed him to improve his team’s performance earlier.

“I didn’t enjoy the first half,” Mourinho said. He added: “Football is very slow to change the rules. How many years have we had to wait for goal-line technology, for the third substitution? I hope I am still in football when they give the coach the chance to stop the game during the first half once and during the second half, because you can make the game much better.

“Imagine today. I would have stopped the game in the 10th minute. It would be interesting. [Louis] Van Gaal in the World Cup, the ref stopped the game for the water break, and he changed the system of his team and managed to win the game; so maybe I will one day have the chance to stop the game in the first half and once in the second half.”

Chelsea were initially rattled by a combative Leicester side, and Mourinho praised the “immense” defender Branislav Ivanovic for shaking the side up. “He is one of the ones from our important days,” he said. “From the mental point of view he belongs to that strong base.”

Costa and Ivanovic have now between them helped give Chelsea’s title challenge an even stronger base.