Cowans told avfc.co.uk: "We're delighted that Nathan was given a first team squad number this season. Whilst he's yet to make the bench, it's important for him to have been around the first team and it also shows another of our players is making the step up.
"This is what we're here for as an Academy and the players have to take their chances to impress. They have to look at people like Gabby Agbonlahor and Craig Gardner and show the same determination to progress."
Cowans believes Clark and Baker could both follow Delfouneso into the senior squad after the defensive duo impressed last term.
He added: "Ciaran plays regularly for England under-19s and has shown a lot of promise and we are hopeful that he will come through. Nathan Baker is another young lad and we are very hopeful of those two. But let's give them time."