The Chelsea youngster has struggled find a way into the first team at his loan club.
But Wales teammate Matondo told The Sun, “When I first came I wasn't playing a lot, I was coming off the bench most of the time.
“I know when he gets his opportunity he'll take it because he's that kind of lad.
“It's just a matter of time, he just has to be patient and keep working hard in training. When he gets the opportunity at Wales camps, he can show Leipzig what he's capable of."