The Republic of Ireland international has been controversially frozen out of the Owls first team this season.
The 34-year-old has not played for the first XI in over 12 months, his last outing coming in the 3-1 loss at Norwich City on December 9 2017.
But Luhukay has revealed the goalkeeper asked to play for the club’s Under-23s this week - he featured for 45 minutes - with speculation linking him with a move in the January transfer window.
"It was a good situation for him to come to practice,” said Luhukay. “He played 45 minutes.
"Keiren asked to play and we gave him the chance.
"It was the first time he had asked to play for the Under-23s.
"It is a decision I respect.
"Keiren is not 18 or 20 years old. He is 34. He knows what is best for him and we accept that.”
Luhukay has opted to select rookie duo Cameron Dawson and Joe Wildsmith as his two match-day goalkeepers this season.
And the Owls boss said he was in the dark over Westwood’s future - out of contract at the end of the season - or reports claiming the Owls rejected a £3m bid from Premier League side Cardiff City last summer. Leeds United have been linked with a January move for the former Sunderland goalkeeper.
"I don't know,” said Luhukay. “I have no contact with the agent or the situation. I can only focus on my team and what players are available and that is my focus.”
Wednesday head to Swansea City on Saturday, missing midfielder Barry Bannan who starts a two-match suspension.