Boro place plenty of emphasis on the production of home-grown talent, with their youth system the envy of many clubs in England.
There is, however, a big step up from the U21 ranks to the senior side and some youngsters are struggling to bridge the gap.
Boro are doing all they can, though, to unlock the obvious potential - with Adam Reach spending time with Shrewsbury Town, Curtis Main just back from a spell at Greenhous Meadow and Luke Williams having already been involved in Championship competition this season.
Mowbray told The Gazette: "I want these lads to show me they have what it takes to affect games in the Championship week in, week out.
"They have lots of ability, lots of talent, but it's a balance. A balance between technique, talent, personality, drive and work rate.
"They probably need to go out on loan and learn the game. It's not just about ability. You have to impact on the match, you have to demand the ball.
"We've seen with Ben Gibson how he benefited from playing in a team alongside men whose livelihoods depend on the result, in grounds where the crowd is on top of you and will get on your back if you make a mistake.
"After doing well at York and Tranmere, he's been able to come into our team and hold his own.
"I hope all of our lads come back from their loan spells all grown up.
"Then they have to go back into the U21s and show me that they deserve to play. They train with the seniors most days, but they have to show me they have the desire to play for the first team."