Cape Town - Chelsea manager Maurizio Sarri says fit-again Ross Barkley is returning to his best form and will prove an important player for the Blues this season.
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The Italian mentor has also backed the 24-year-old to give England manager Gareth Southgate a headache when he selects his starting line-up for the upcoming UEFA Nations League matches with Croatia and Spain.
Barkley scored his first goal for the London outfit in the 3-0 over Southampton over the weekend and recently made a return to the Three Lions squad after a long absence due to injuries.
"I am really happy with him. He has improved week by week, day by day and match by match," Sarri told Sky Sports.
"He had a very serious injury in the last two seasons, he is improving day by day and I think the best will come.
"I said from the first day that he has great physical and technical quality. But you have to improve from the tactical point of view and now he has improved I think.
"Potentially, he is a great player. He has quality - very important quality from the physical point of view. From the technical point of view, he is improving tactically.
"He will become a very important player, and for the England national team."