Richards missed Wednesday's 3-0 win at Liverpool in the Carabao Cup, suffering from a minor calf issue.
Forward Nketiah did start at Anfield, but came off at half-time, with Jean-Philippe Mateta replacing him for the second-half. Wharton travelled up for the match, but withdrew from the matchday squad due to illness.
Asked about how his squad ahead of the Brentford game, the Manager gave an update on the trio: “We had a scan [on Nketiah] yesterday. The result came back and was better than what our [original] concerns were.
"It's a minor muscle injury. It looks like he'll be back after the international break. So he will miss three games but then should be back. It's a positive result from the scan.
"Chris Richards is back tomorrow so he is fine. He trained today without any issues.
"We tried to manage the minutes here with resting him against AEK Larnaca, but you can't cheat your body. Your body tells you when you need to rest and Chris' body told us that he needs more rest – so let's see.
"I haven't taken the final decision – if I start him tomorrow, he can, he's fine, everybody says he's fine, or we'll play Jaydee [Canvot] again.
"We will miss Adam [Wharton] again, he is ill. He is getting better, but he had fever and we don't and can't take any risks.
"We have a responsibility to the players, so that means he will miss this game. Hopefully he is available for [Thursday against] Alkmaar."
Outside of Nketiah and Wharton, Glasner has no other fresh selection issues, confirming that: "All the others are fine."