The Denmark international playmaker has entered the final 12 months of his current deal in north London.
There has been no indication that he is looking to commit to fresh terms, with transfer talk continuing to rage around him as a result.
Spurs are still hoping that a compromise can be reached, allowing them to avoid a sale or free agency, but discussions have not progressed as they had hoped.
Eriksen is said to still be keeping his options open, with a move to Madrid having been mooted for some time.
Former Tottenham striker Crouch can understand the appeal of life at a Spanish giant, but feels a proven Premier League performer needs to recognise how good he has it in England.
Ex-Spurs star Bale has shown how quickly things can unravel at the Santiago Bernabeu, even when helping to deliver an enviable collection of trophies, with the Welshman held up as an example to Eriksen.
Crouch told the Daily Mail of a long-running saga involving a talented 27-year-old: “He has been superb for Tottenham and has a manager who really trusts him.
“Harry Kane scored the goals that ultimately defeated Villa [on the opening weekend of the 2019-20 campaign] but it was only when the Dane came on that they really went through the gears.
“But as he has shown no indication that he will sign a new contract, you cannot rule out the idea that Tottenham will sell him before the window closes.
“Real Madrid is the club he wants to join but I wonder whether it would suit him.
“I moved many times during my career and you realise occasionally the grass isn't always greener.
“Would Madrid suit him? He wouldn't be the main man there and could end up lost.
“Eriksen is talented and professional but that doesn't guarantee anything in Madrid. Look at Gareth Bale.”
Bale has been heavily linked with a switch of his own this summer, but no transfer has been put in place and Zinedine Zidane has been left with little choice but to draft him back into his plans.
Mauricio Pochettino is taking the same stance with Eriksen at Tottenham, with the Argentine adamant that he will not allow exit rumours to impact his selection calls.