When the team sheet was released ahead of Sunderland’s Checkatrade Trophy clash against Notts County, there was some confusion as to how the Black Cats would line-up.
Jack Ross has altered between different formations this campaign, but with only one recognised full-back in the starting XI, Bryan Oviedo, it wasn’t clear who would occupy the opposite flack - in a back three or a back four.
When the game kicked-off it soon became clear that 17-year-old Bali Mumba had been chosen to operate as a right wing-back in a 3-5-2 formation.
Mumba's maturity both on and off the pitch has impressed many this year, following the teenager's first-team debut on the final day of last season.
Most of Mumba’s performances in a red and white shirt, for the first team and the under-23 side, have come in the centre of midfield, but, as Ross pointed out earlier this week, Mumba has operated at full-back on international duty with England Under-18s.
The Notts County game, which Sunderland won 2-0, provided a stern test for Mumba, who came face to face with 31-year-old defender Dan Jones.
But after taking some early hits in the first 45 minutes, the Sunderland man grew in confidence and looked a more natural fit in the second half.
“It was tough for me out there. (In the) first half particularly it took me a while to get into it,” said Mumba after the game.
“I knew I had to do better, that's why in the second half I came out with more confidence, I got at them more rather than sitting back.
“I was playing high up the pitch and that's what I liked. That gave me the strength to get on the ball.
“It was tough out there but I thought I dealt with it well, especially in the second half.”
Mumba adapted to the role so well that he even had an opportunity to score a third goal for Sunderland late on, but was denied by goalkeeper Ross Fitzsimons.
“I'm gutted about that but it's coming,” said Mumba when asked if he thought he was going to score.
“I believe that, I have faith. I just need to keep pushing and I know my time will come. I just need to keep working hard and see what happens.
“I thought if I went with my left foot the defender was coming in hard but I need to watch it again to see what decision I could have made.
“Definitely next time I believe it will be different.”
So how does Mumba feel about playing as a full-back when his game appears suited to central midfield?
At the moment the teenager is happy just to be playing and isn’t set on one particular position.
“That's a difficult one,” said Mumba when asked about his favourite position.
“Many people have asked me that and I don't have an answer. I'm just an all round player, I would say – midfield, full-back, I'm not really too fussed as long as I get the experience.”
“I want to be a player who’s able to play in different positions be all round.
“If the gaffer gives me a task to do, I just want to be able to do it for the team and get on with it, don’t worry about it’s not my position, just have that mindset of this is my job.”