"He is still struggling a bit and looks very weak but fingers crossed he will be fine," Gray said.
Cobblers will also be without suspended striker Adebayo Akinfenwa as he commences a four-game ban following his sending off against Brighton.
Meanwhile, midfield duo Liam Davis (hernia) and Luke Guttridge (knee) are still unavailable but are likely to return to training on Monday.
Northampton will be without goalkeeper Ron-Robert Zieler who returned to parent club Manchester United following the expiry of his loan deal this week, so Chris Dunn should deputise with Paul Walker being promoted from the reserves to the bench.
The Cheltenham side won't feature Alex Russell after he completed a move to Exeter.
The midfielder has joined the Grecians on loan until the end of the season when he will then complete a permanent switch to the League Two club.
The Robins are stuck at the foot of the League One table having lost their last six games and a result against the Cobblers, who have won just one of their last 10, is a must if they are to climb out of trouble.
On-loan forward Ashley Hemmings made his debut for the club as a late substitute in the 3-1 defeat against Millwall on Tuesday and he is again looking to be involved.
Defender Alan Wright remains sidelined with a calf injury while striker Damian Spencer is also struggling with a knock.
Winger Michail Antonio (ankle) and defender Michael Townsend (hamstring) remain out.
Sporting Life