The 42-year-old has been spotted watching Wolves and Villa’s under-23 sides in recent months ahead of the January transfer window.
And with wingers his priority this month, Clarke has said it’s not likely he will sign several young players on temporary deals.
“Under 23 players are everywhere, loans are everywhere,” he said.
“I’ve already got four loans at the football club so I can only have one more loan.
“I don’t like six or seven loans because you can only have five on your team sheet.
“There’s thousands of those boys available.
“I go to a lot of U23’s games and they’re very similar, it’s very hard to place players.
“Managers will tell you in League One and League Two that they’re very hard to place into our environment.
“In an ideal world you like players that have been out on loan before and done well.
“The ones that come to you first of all, it’s a big wake up call.
“We produce a system through the academy with technically better players, without a shadow of a doubt, but we also produce mentally not strong enough players.
“What you have to bear in mind is that in U23’s football the transition of the football is a lot less than what it is in a League Two game.
“The transition in a League Two game is maybe three or four passes, max four or five.
“In an U23’s game they’ll have nine or 10 passes.
“For me players have to be fitter when they come into League Two, they have to be more aware of their defensive duties.
“Everyone is keen on players on the eye but it’s a different ball game coming from U23’s football to first team football.”
Meanwhile, Clarke has refused to comment on the future of James Hardy.
The 23-year-old hasn’t played since December 29 and has been replaced on the bench with academy talents in recent weeks.
His last start for the club came on August 31 but Clarke remained coy on the midfielder’s future.
“The conversations I have with my players, you’ll respect this is a private matter,” he added.
“James Hardy is technically a very gifted player but I need more from him, like I need more from my other players for them to hold down a regular first team slot.
“So we’ll see what develops through the course of the window.”