Bristol - England coach Eddie Jones refused to reveal why he had left Ben Te'o out of his 31-man squad for the World Cup announced Monday.
New Zealand-born Te'o lost out to Piers Francis among four England centres, despite being an ever-present choice under Australian boss Jones when available.
The 32-year-old was reported to have been involved in a scuffle with Mike Brown at the England squad's training camp in Italy a fortnight ago.
And now the 18-times capped midfielder, who has two Test appearances for the British and Irish Lions to his credit, failed to make the World Cup squad.
"I'm not going to go into reasons why he (Te'o) was not selected," Jones said.
"We have had that conversation with Ben, he understands it," the former Australia and Japan coach added.
"He's not in our top 31 players at the moment."
But Jones did leave the door ajar to a late call-up although he would not confirm if Te'o -- or indeed anyone else -- was on a standby list.
"Obviously a number of very disappointed players," he said. "We feel for them.
"The message we have for them is that they have still got to be ready because the circumstances of the World Cup dictates that you have injuries."
In contrast to Te'o uncapped former sevens specialist Ruaridh McConnochie was included following the wing's strong end to the season for Bath.
Scrumhalf Willi Heinz, flanker Lewis Ludlam and hooker Jack Singleton, who all made their debuts in Sunday's 33-19 World Cup warm-up defeat of Wales, were also selected.
"Firstly I think it's always nice to bring new blood in, it always freshens things up," Jones said.
"Ruaridh we've been watching quite closely through the club season. I was impressed by him.
"Lewis came from nowhere. We watched him in club rugby, he'd done particularly well and we thought we'd roll the dice and bring him into camp to see what he could offer."
Owen Farrell -- who did not play on Sunday -- has retained the captaincy, with the Saracens star one of two flyhalves along with George Ford but, as expected, Danny Cipriani was not included.
Meanwhile former captain Dylan Hartley was omitted following the hooker's long-term absence through concussion and then a knee injury.
England have won the World Cup just once, when they beat an Australia side coached by Jones in the 2003 final in Sydney.
Jones has named his squad nearly a month ahead of World Rugby's September 8 deadline, with England still to play three warm-up fixtures -- a return clash against Wales in Cardiff on Saturday followed by matches against Ireland and Italy.
Jones, who took over as England coach following their embarrassing-first round exit on home soil at the 2015 World Cup, said that experience had played a part in announcing the squad early.
"We have taken the decision to go early because of what we learnt from previous campaigns," he said.
"We want the squad to know early and now we can get on and be the best prepared England side there has ever been, ready to win the World Cup."
England begin their 2019 World Cup pool campaign against Tonga in Sapporo on September 22.
England's 2019 World Cup squad:
Joe Cokanasiga (Bath), Elliot Daly (Saracens), Jonny May (Leicester), Ruaridh McConnochie (Bath), Jack Nowell (Exeter), Anthony Watson (Bath), Piers Francis (Northampton), Jonathan Joseph (Bath), Henry Slade (Exeter), Manu Tuilagi (Leicester), Owen Farrell (Saracens, capt), George Ford (Leicester), Willi Heinz (Gloucester), Ben Youngs (Leicester)
Tom Curry (Sale), Maro Itoje (Saracens), George Kruis (Saracens), Courtney Lawes (Northampton), Joe Launchbury (Wasps), Lewis Ludlam (Northampton), Sam Underhill (Bath), Billy Vunipola (Saracens), Mark Wilson (Newcastle/Sale), Dan Cole (Leicester), Luke Cowan-Dickie (Exeter), Ellis Genge (Leicester), Jamie George (Saracens), Joe Marler (Harlequins), Kyle Sinckler (Harlequins), Jack Singleton (Saracens), Mako Vunipola (Saracens)
England World Cup pool fixtures:
September 22: v Tonga, Sapporo
September 26: v USA, Kobe
October 05: v Argentina, Tokyo
October 12: v France, Yokohama