Doubts persist over the former Liverpool right-back's defensive game, which Parker admits could be exploited unless major improvements are made.
Parker told Tribalfootball.com: "It will definitely be up there, and he will have to be careful that he doesn’t get white handkerchiefed! I saw it in the semi-final that Carvajal came on and that’s the person that he’s up against, a proper right back, a great right back that has won everything.
"Tenacious, aggressive, gets forward well and gets to the by-line. If you want to go to Madrid and you think you’re in the Hollywood of football to play the Hollywood passes and think that’s gonna favour you? I don’t think it’s gonna be that way. I think he needs to get back to real football."
On whether Dani Carvajal should be kept on by Real Madrid, Parker was adamant.
He continued: "I would start Carvajal over Trent. I think you must allow him the opportunity to prove that after his ACL he is still the same player, but that can make a massive difference. You have to wonder who signed Trent, was it the outgoing manager, the incoming manager – and I don’t think Xabi Alonso would sign him… but looking at it you do wonder.
"I think if he was England’s number one right back it would make sense, but he isn’t even England’s best right back. At the end of the day, that’s because he’s never been a right back because he can’t and won’t defend."
- Paul Parker was speaking exclusively to Tribalfootball via the home of betting