Antonio Conte believes Ross Barkley is a “complete player” and the Chelsea manager hopes the midfielder can fulfil his potential at Stamford Bridge. Conte warned it would take Barkley time to find his feet after the 24-year-old joined from Everton for £15m on a five-and-a-half-year contract.

Barkley has only just returned to training following a hamstring injury that needed surgery and has kept him out all season; his last appearance was for Everton on 21 May at Arsenal. But there was excitement and anticipation in Conte’s words as he reflected on what feels like a coup.

Chelsea were poised to pay £35m for Barkley last summer and the four-month delay in concluding the deal has cost Everton £20m in transfer revenue. The player’s contract there had been due to expire at the end of the season and, with Barkley showing no inclination to renew at his boyhood club, Everton were forced to reluctantly accept the fee.

“We are talking about a player with great potential,” Conte said. “He is a complete player but, at the same time, he is very young. He is complete because he has it all. He has stamina, he is strong physically and he has good technique. He is fast. He is a modern footballer.”

Barkley, who will wear the No8 shirt, said: “I’m overwhelmed. I’m looking forward to it and I’m really excited to get started. To be given a fresh start at a new club like Chelsea – it’s unbelievable for me. I’m looking forward to continuing where I left off at the end of last season and hoping to improve and add more goals to my game.”

Conte has sometimes used a 3-5-2 formation this season – hence the need for another body in central midfield – and he mentioned how it was always preferable for the club to sign English players, particularly as they had lost John Terry, Frank Lampard and Ashley Cole in recent years. Barkley has 22 caps.

Conte has been linked with a move for the West Ham United striker Andy Carroll, which he did not rule out at his press conference on Friday, and he signed the midfielder Danny Drinkwater from Leicester City last summer. Gary Cahill is the other English player in Conte’s senior squad.

“An English player understands very well this league because you grow [up] in this league,” Conte said. “For Chelsea, also, it is positive to buy English players because we lost important players like John Terry and Frank Lampard.”

Conte made it clear that he wanted to strengthen in more than one area during January – “there is the priority to improve this team, especially in some roles,” he said – and, for him, the sooner the club can complete incoming deals the better.

“Our start to the season was poor because many players arrived in the last moment and also injured,” Conte said. “[Tiémoué] Bakayoko was injured and Drinkwater too. [Davide] Zappacosta arrived in the last moment. If I have the opportunity to work soon with the new players it will be better for my team and the new players, so they can adapt in our idea of football.”

Barkley was on the brink of a deadline-day transfer to Chelsea last summer only to request more time to consider the move as he recovered from his injury.

Conte offered an insight into the transfer processes at Chelsea. “I like to tell the club which is the role we can improve, which is the prospect and [what are] the characteristics of the players I need,” he said. “Then the club try to help me. There is one list, two list, three lists and, sometimes, you can take the first name and, sometimes, the last name of the list. This is for the club [to decide]. But, for sure, when you take a player that is the first on the list, the improvement will be better.”