Khan has been sidelined for almost three months with an ankle injury and has stepped up his rehabilitation with some individual ball work.
Smith’s medial knee ligament issue has kept him out of action for six weeks but the defender has made progress over the last week.
“Otis has been training this week but we’ve got to make a decision on him,” Darren Way told YTFC.net.
“Nathan has been doing very well this week and falls in the same category.
“We don’t want to push them too early.”
Alex Lawless is a doubt due to a hamstring complaint which has seen him miss Town’s last two Sky Bet League Two fixtures.
Captain Darren Ward (knee) is out for the remainder of the campaign.