The Villa manager doesn't mind Vlaar attracting further interest during the final month of the season, as it will mean he is impressing on the pitch.
Vlaar, 30, is out of contract at the end of the season but talks over an extension have been put off as the club look to secure Premier League survival with four matches remaining.
Speaking to the Birmingham Mail, Sherwood stressed that he remains eager to tie the veteran centre-back down to a new deal but knows that he will be in the shop window during the run-in.
“Once he’s on the pitch he’s in the shop window,” said the Villa boss. “So I want to make sure I keep him in that shop window, not only for his benefit but for the benefit of the football club because Ron Vlaar on the pitch will enhance us.
“If there’s a contract decision to be made, whether he stays at this club or joins somewhere else, we’re going to make an adult decision.
“Ron is a man of a lot of experience now and I’m sure we will have a quite honest and frank decision to make.”
Vlaar has endured a frustrating season since returning from an impressive World Cup campaign with Louis van Gaal’s Netherlands side, having seen injuries limit him to just 18 total appearances and lost the captain’s armband to Fabian Delph.
Nevertheless, a reunion with now-Manchester United boss Van Gaal has been mooted since the summer, per the likes of the Telegraph, while SportItalia’s Alfredo Pedulla has also reported that Serie A giants Juventus and Roma remain eager to acquire his services.
The fit-again defender has suggested that he would be open to penning a new Villa deal, though, telling the Telegraph of how Sherwood’s appointment has changed things for him.
Asked about his future following the recent 2-1 FA Cup semi-final over Liverpool, Vlaar said: “I don’t know, it’s hard to say, but things have changed for me in the past few months since Sherwood took over.
“It wasn’t so good earlier in the year and it’s never good when someone has to go but it felt like a fresh start. Is it possible I could stay at Villa? Yes it is. I want to win the FA Cup anyway, no matter what, and then we will see what happens.
“It’s not something to think about right now. Beating Liverpool feels really great and I also feel things have changed at the club.”
During his frequent spells on the sidelines, Vlaar has seen fellow centre-backs Ciaran Clark and Jores Okore strike up a superb rapport at the heart of the Villa defence, with the pair’s form leading to suggestions that he could be made expendable.
However, the former skipper has impressed since returning to the line-up in recent weeks from a nagging calf problem, starting the past four games, and now looks set to fill a crucial role during the club’s bid to retain their top-flight status and secure a first FA Cup title since 1957.
If he can help them do both then there’s little doubt that Villa’s management will have a new contract offer for him on the table as soon as the season is up, although whether he is willing to sign it is another matter.