Robbie Deans says England missed an opportunity to test their players against New Zealand by preventing them from representing the Barbarians.
James Haskell, Semesa Rokoduguni, Jonathan Joseph and Kyle Sinckler are understood to have been among a contingent of Eddie Jones' stars who were approached to take part in Saturday's match at Twickenham.
Many initially agreed only for either their interest to wane amid pressure from injury-hit clubs or circumstances to change, such as Sinckler's seven-week ban for gouging.
England face New Zealand at Twickenham next autumn in a long-awaited clash between the world's top two teams and Deans believes that, by playing for the Barbarians, some of their Red Rose stars could have gained valuable exposure to the All Blacks.
Jones' has been overseeing a warm-weather training camp in Portugal this week ahead of the autumn series, but Deans believes there are some who could have been given the green light to face Steve Hansen's men.
"It's a great shame for those England players and it was a great opportunity for them to experience the level," said Barbarians coach Deans, whose team lost 31-22. "So it's been an opportunity missed because some of those 23 could have had a taste of this.
"They were all pretty much positive early on, but when it comes down to it they get into the season, injuries pick up and internationals loom, things can change.
"The initial positivity was replaced by a little resistance. The players felt a little bit of pressure that they might compromise themselves if they stepped into this.
"A player is always going to listen to his international coach in this circumstance, but to a man they all wanted to play." New Zealand pulled clear in the third quarter, but head coach Hansen felt referee Nigel Owens got caught up by the nature of the occasion.
"We might have got caught up in the whole festival of the occasion, which is natural, so we threw some wide passes," Hansen said.
"Most of the banter came from Nigel. It would have been good had he reffed this game.
"It's a festival game and he's like the rest of us, falling into the trap. There's no doubt in my mind that he wasn't as focused as he would be if it was a Test match."