Frank Lampard believes the in-demand Callum Hudson-Odoi needs to improve off the ball to reach the next level, particularly when it comes to implementing Chelsea's pressing system.
Hudson-Odoi made his first Premier League start since the UK lockdown due to coronavirus in the 4-0 win over Crystal Palace on Saturday.
That lack of minutes in the league had prompted Bayern Munich to believe that they could convince Hudson-Odoi to move to the Bundesliga champions.
Chelsea have rejected Bayern's attempt to sign the 19-year-old on loan with a view to a £70 million ($89m) deal for the England international in 2021, with talks set to continue ahead of the transfer window closing on Monday.
With his future in doubt, Lampard was asked to compare Hudson-Odoi with Willian, who left to join Arsenal this summer, and assess his game with the spotlight firmly on the young winger.
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"I am not sure I want to compare him to Willian, they both have some aspects but they are not as similar as you might think," Lampard said at Stamford Bridge.
"With Callum, his work off the ball is something I am trying to improve because at this level in the Premier League, you see how we worked last year, and Willian was the first trigger in us winning the ball back.
"He covered so much ground in high areas, at speed, off the ball. Wingers have to have that mindset these days. That's something I put on Callum and he has to improve on little bits and he did better, but he can still do more.
"I think Callum's natural ability is on the ball, taking people on the outside and that's what he can do, and those things will come out as Callum keeps developing. As he builds confidence, he needs to know that I am behind him in that sense because he can bring a lot. Then, we will see a lot more from Callum.
"We have to remember he had a very difficult injury to overcome at a very young age. It is not easy to do that when you are a player with pace, trickery and explosiveness of that nature.
"I think this season Callum can offer a lot for us in those terms because of his natural ability."