Hardy had been a regular starter while Williams’ is the Bucks’ second top scorer so far, with three goals, but both have been among the substitutes for the last two games.
And Cowan, whose side are hoping to grab an important win at Bradford Park Avenue tomorrow, has urged the pair to have the bit between their teeth.
“It’s not really in my control, it’s up to them,” said the Telford chief.
“The man-management element is a strong one of mine.
“If they are left out of the team then I’m very honest, I’ve been very honest with the players as to why they’ve been left out the team.
“Some players I don’t need to speak to, there’s an understanding there.
“But ultimately they have to react, I can’t do that bit for them. You have to have your own personal pride, a bit between your teeth. It’s the making of the character.”
Hardy’s signing over the summer after a season at Walsall was one which excited fans, while Williams – only behind Jason Oswell, with four, in the scoring charts – had also been a consistent presence in Telford’s front three.
Dom McHale and Jordan Davies have been preferred as of late, though, with Cowan’s charges grabbing a 2-1 win at Darlington last weekend before a disappointing 1-0 loss to Chorley on Tuesday at the New Bucks Head.
“I believe those players will find their way. They have to work hard in training,” said Cowan. “I can’t pick teams off the back of games, I have to off the back of training as well.
“If they want to get back in that much, they have to work that bit more harder and have more diligence and focus.”
On whether he wants the pair to be frustrated over their current predicament, Cowan added: “Absolutely.
“I think there was a game recently where I took Adam Walker off.
“He doesn’t want to come off, he’s fuming, but he totally respects the decision.
“Equally, on my side, I respect the fact that Adam is fuming, because he’s not done enough and his ego is hurt a little bit.
“It’s never anything personal, it’s all for the gain of the club and to get three points, which we need to do more of.”
Telford, meanwhile, will be without injured quartet Shane Sutton, Henry Cowans, Brendon Daniels and Courtney Meppen-Walters for the trip to mid-table Avenue.
The Bucks are sixth in National League North but are looking to find some momentum after losing four of their last six outings.