The 17 year-old striker started both EFL Cup victories over Shrewsbury Town and QPR, while he has made one sub appearance in the Premier League.
“With Jermain missing the recent QPR match, we had to put two boys in the squad," said Moyes.
“But it was great though that those boys – Joel and Josh – have played at a Championship club away from home.
“Joel started, alongside Duncan Watmore up front, and Josh Maja came on in the second half and got some game time under his belt.
“For them, you hope that somewhere along the line, they will get the benefit.
“I think Joel produced an even better level from the Shrewsbury game – he was better again against QPR.
“They still need to make sure they can score, but I think they can cause problems with their movement.
“But, at 17, he is doing really well, the boy."