Henderson is approaching the end of his second season with Chris Wilder’s side, having returned to South Yorkshire last summer after helping United reach the Premier League last term.
Seemingly poised to win his first senior international cap following a series of impressive displays in the top-flight, Henderson’s parent club Manchester United are facing calls to summon the youngster back to Old Trafford when their agreement with Wilder’s employers expires and name him as David de Gea’s successor.
But Turner, who made 81 appearances for the 20-time English champions during his own playing career, has told Ole Gunnar Solskjaer it makes sense for him to grant United’s request to extend Henderson’s stay before handing him the chance to succeed the Spaniard.
“He’s on contract at United for another two years but clearly he is making great strides and is proving himself a top keeper in the making,” said Turner.
“In many ways he’s in a great position but his next step is vital and the worry for United is that if he doesn’t see a way past De Gea he’ll want to leave.
“He won’t be happy to go back and sit in United’s reserves and you couldn’t blame him because he has the potential to be a fantastic keeper.
“I’m sure United know that, and that’s why it’s such a tough decision for Solskjaer.
“I can’t see Solskjaer shoving De Gea out of the first team to make way for Dean. He’s recently signed a big long-term deal and is firmly established.
“He’s proved himself a top keeper the last few years and, although he’s made some mistakes the last year or so, he’s still one of the very best around.”
Wilder, whose side had climbed to seventh in the table and reached the quarter-finals of the FA Cup before competition was suspended due to the coronavirus pandemic, approached Manchester United about the possibility of renewing Henderson’s loan for a second time before Christmas.
Speaking to a national newspaper, Turner, who appeared more than 200 times for Wednesday during his own playing career, said: “De Gea broke into the first team when he was only 21. Henderson is already two years older and I’m certain he could do the job but ditching De Gea would be a huge call.
“The best solution might be another season on loan with the Blades. He can get all the fulfilment he needs there while he continues to develop at a good club doing very well in the Premier League."
“I live in Sheffield and have watched plenty of him,” Turner added. “I’ve been at the Blades training ground and chatted with Chris Wilder who says Henderson is very motivated and believes in himself.
“He’d love to keep him permanently but he’d cost a lot of money in a fee and wages.”