Gray has been sidelined since the end of last season with a split tendon but could be named amongst the substitutes for the game at Vicarage Road after playing in a reserve game in midweek against Cambridge.
"I will be assessing his fitness for a 24 hour period and then make a decision," Francis told the clubsofficial website.
"I would be delighted to have him back. He gives us tremendous mobility on the left when he does play and I am hopeful he will make the trip."