#1 Tammy Abraham
The 20 year-old striker is currently on loan at Swansea City and has not quite matched the 26 goals from last season - when he played for Bristol City in the Championship. However, he still has a future at Chelsea ahead of him.
He made his England senior debut in November 2017 against Germany at Wembley, which suggests he is rated highly by the national team boss, Gareth Southgate. He may potentially have one more campaign out on loan, most likely to another Premier League outfit, before breaking into Chelsea's team.
This is because he has only scored 4 times for Swansea City in the league this season and could do with going to a team where he is a regular starter and not used as an impact substitute. He is a tall and powerful front man and is a good plan B option for the Blues in the future.
The verdict
Many youngsters at Chelsea will never break into their first-team due to the sheer number of players they have in their ranks. Nevertheless, the five that have been mentioned have the ability and potential to be key players in the future if they continue their development.