Mauricio Pochettino says in-form Noni Madueke needed to improve his mentality to become a fully-fledged Chelsea player.
The 21-year-old winger could start against Preston in the FA Cup third-round match on Saturday evening after scoring in his last two matches.
A crucial match-winning penalty at home to Crystal Palace was followed up by a wonderful strike away at Luton in only his second Premier League start of the season.
But Pochettino admits he initially overlooked Madueke as he struggled to show the mentality and behaviour required to make it at this level.
He said: “I am so happy, it took him nearly six months to realise what we expect from him. Players need to improve and he is improving a lot. His behaviour now and how he has committed to himself first, and with the rest of the ideas from the club.
“He has potential and talent in the way that he needs to do the things and behave in the future if he wants to succeed.
“That is the platform for everyone and then it is about being right in your mind and be consistent in the way we propose they behave.”
Madueke was dropped and criticised by his manager earlier in the season after being filmed in a nightclub in Mayfair during an international break.
Pochettino was also at Tottenham when 16-year-old Madueke chose to leave and join PSV Eindhoven in 2018. The Argentine, however, denied the exit had anything to do with him.
“He was 16 when I was there; we knew him because we followed the players in the academy at Tottenham, but he was a talented player," he added.
Chelsea will play close to their strongest team in the FA Cup on Saturday despite facing lower-league opposition. It owes to the importance of the match, which could not only keep a chance of silverware alive, but the domestic cups also offer an extra route into Europe.
Ten players are out injured, and after revealing Christopher Nkunku is only fit enough for the bench, he gave a similar update about Ian Maatsen.
"He was injured during the week and could not train," he said. "Yes, problems in his back. Now he came back in training and will be involved in the squad, not play [from the start] but be involved in the squad.
"He suffered a small injury but now I think he will cover to arrive but not play. How many things people don’t know and criticise us but, no, he is not going to play because he hasn’t trained for two days."
Maatsen is in talks over a possible transfer to Borussia Dortmund in January but, when pressed, Pochettino couldn't offer any insight into the situation: "No, that’s rumours, no. The club didn’t announce it. Tomorrow, he is going to be involved in the game."
He was also asked whether recalled Nottingham Forest loanee Andrey Santos could boost the squad, adding: "We will see, we will see. Also, we need to assess the squad for the players who can go on loan.
"We decided to bring him back because he wasn’t involved in the squads at Nottingham Forest. He wasn’t involved every week.
"It is good for him to come back, assess him and take the best decision for him and the team."
