Keane has missed Wednesday's last six matches through injury, but is due to return to the club next week and Gray will be looking forward to having him back at his disposal.
The Owls boss believes that he had just started to show his top form before being sidelined and will be hoping that the striker hits the ground running when making his return to competitive action.
“His attitude and application have been fantastic,” Gray said. “We were seeing the best of Will and unfortunately he got injured. He is a quality player at a big club.”
Keane had scored three goals in his first 11 matches for Wednesday, but will only have two more games in which to increase that tally when he does return.
That is unfortunate for Wednesday as they have struggled for goals this season and Keane had threatened to end that problem.
The Yorkshire club may be tempted to try and secure another loan deal for the 22-year-old next term, but it remains to be seen whether they will push ahead with a deal.
The two games Keane will come back into contention for are against Leeds United and Watford, and he will be hoping to show his class once again during those fixtures.